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2013-12-16serial: 8250_dw: Fix LCR workaround regressionJames Hogan
Commit c49436b657d0 (serial: 8250_dw: Improve unwritable LCR workaround) caused a regression. It added a check that the LCR was written properly to detect and workaround the busy quirk, but the behaviour of bit 5 (UART_LCR_SPAR) differs between IP versions 3.00a and 3.14c per the docs. On older versions this caused the check to fail and it would repeatedly force idle and rewrite the LCR register, causing delays and preventing any input from serial being received. This is fixed by masking out UART_LCR_SPAR before making the comparison. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Tim Kryger <tim.kryger@linaro.org> Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Cc: Matt Porter <matt.porter@linaro.org> Cc: Markus Mayer <markus.mayer@linaro.org> Tested-by: Tim Kryger <tim.kryger@linaro.org> Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-16tty: Fix hang at ldsem_down_read()Peter Hurley
When a controlling tty is being hung up and the hang up is waiting for a just-signalled tty reader or writer to exit, and a new tty reader/writer tries to acquire an ldisc reference concurrently with the ldisc reference release from the signalled reader/writer, the hangup can hang. The new reader/writer is sleeping in ldsem_down_read() and the hangup is sleeping in ldsem_down_write() [1]. The new reader/writer fails to wakeup the waiting hangup because the wrong lock count value is checked (the old lock count rather than the new lock count) to see if the lock is unowned. Change helper function to return the new lock count if the cmpxchg was successful; document this behavior. [1] edited dmesg log from reporter SysRq : Show Blocked State task PC stack pid father systemd D ffff88040c4f0000 0 1 0 0x00000000 ffff88040c49fbe0 0000000000000046 ffff88040c4a0000 ffff88040c49ffd8 00000000001d3980 00000000001d3980 ffff88040c4a0000 ffff88040593d840 ffff88040c49fb40 ffffffff810a4cc0 0000000000000006 0000000000000023 Call Trace: [<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4 [<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4 [<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4 [<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4 [<ffffffff817a6649>] schedule+0x24/0x5e [<ffffffff817a588b>] schedule_timeout+0x15b/0x1ec [<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4 [<ffffffff817aa691>] ? _raw_spin_unlock_irq+0x24/0x26 [<ffffffff817aa10c>] down_read_failed+0xe3/0x1b9 [<ffffffff817aa26d>] ldsem_down_read+0x8b/0xa5 [<ffffffff8142b5ca>] ? tty_ldisc_ref_wait+0x1b/0x44 [<ffffffff8142b5ca>] tty_ldisc_ref_wait+0x1b/0x44 [<ffffffff81423f5b>] tty_write+0x7d/0x28a [<ffffffff814241f5>] redirected_tty_write+0x8d/0x98 [<ffffffff81424168>] ? tty_write+0x28a/0x28a [<ffffffff8115d03f>] do_loop_readv_writev+0x56/0x79 [<ffffffff8115e604>] do_readv_writev+0x1b0/0x1ff [<ffffffff8116ea0b>] ? do_vfs_ioctl+0x32a/0x489 [<ffffffff81167d9d>] ? final_putname+0x1d/0x3a [<ffffffff8115e6c7>] vfs_writev+0x2e/0x49 [<ffffffff8115e7d3>] SyS_writev+0x47/0xaa [<ffffffff817ab822>] system_call_fastpath+0x16/0x1b bash D ffffffff81c104c0 0 5469 5302 0x00000082 ffff8800cf817ac0 0000000000000046 ffff8804086b22a0 ffff8800cf817fd8 00000000001d3980 00000000001d3980 ffff8804086b22a0 ffff8800cf817a48 000000000000b9a0 ffff8800cf817a78 ffffffff81004675 ffff8800cf817a44 Call Trace: [<ffffffff81004675>] ? dump_trace+0x165/0x29c [<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4 [<ffffffff8100edda>] ? save_stack_trace+0x26/0x41 [<ffffffff817a6649>] schedule+0x24/0x5e [<ffffffff817a588b>] schedule_timeout+0x15b/0x1ec [<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4 [<ffffffff817a9f03>] ? down_write_failed+0xa3/0x1c9 [<ffffffff817aa691>] ? _raw_spin_unlock_irq+0x24/0x26 [<ffffffff817a9f0b>] down_write_failed+0xab/0x1c9 [<ffffffff817aa300>] ldsem_down_write+0x79/0xb1 [<ffffffff817aada3>] ? tty_ldisc_lock_pair_timeout+0xa5/0xd9 [<ffffffff817aada3>] tty_ldisc_lock_pair_timeout+0xa5/0xd9 [<ffffffff8142bf33>] tty_ldisc_hangup+0xc4/0x218 [<ffffffff81423ab3>] __tty_hangup+0x2e2/0x3ed [<ffffffff81424a76>] disassociate_ctty+0x63/0x226 [<ffffffff81078aa7>] do_exit+0x79f/0xa11 [<ffffffff81086bdb>] ? get_signal_to_deliver+0x206/0x62f [<ffffffff810b4bfb>] ? lock_release_holdtime.part.8+0xf/0x16e [<ffffffff81079b05>] do_group_exit+0x47/0xb5 [<ffffffff81086c16>] get_signal_to_deliver+0x241/0x62f [<ffffffff810020a7>] do_signal+0x43/0x59d [<ffffffff810f2af7>] ? __audit_syscall_exit+0x21a/0x2a8 [<ffffffff810b4bfb>] ? lock_release_holdtime.part.8+0xf/0x16e [<ffffffff81002655>] do_notify_resume+0x54/0x6c [<ffffffff817abaf8>] int_signal+0x12/0x17 Reported-by: Sami Farin <sami.farin@gmail.com> Cc: <stable@vger.kernel.org> # 3.12.x Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-16Merge 3.13-rc4 into tty-nextGreg Kroah-Hartman
We want the fixes in here as well.
2013-12-14serial: sh-sci: Convert to clk_prepare/unprepareLaurent Pinchart
Turn clk_enable() and clk_disable() calls into clk_prepare_enable() and clk_disable_unprepare() to get ready for the migration to the common clock framework. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Acked-by: Magnus Damm <damm@opensource.se> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-14serial: sh-sci: Don't enable/disable port from within break timerLaurent Pinchart
The break timer accesses hardware registers and thus requires the port to be enabled. It currently ensures this by enabling the port at the beginning of the timer handler, and disabling it at the end. However, the enable/disable operations call the runtime PM sync functions, which are not allowed in atomic context. The current situation is thus broken. This change relies on non-atomic code to enable/disable the port. The break timer will only be started from the IRQ handler, which already runs with the port enabled. We just need to ensure that the port won't be disabled with the timer running, and that's easily done by just cancelling the timer in the port disable function. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Acked-by: Magnus Damm <damm@opensource.se> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-12serial: sh-sci: Fix warnings due to improper casts and printk formatsLaurent Pinchart
Use the %zu and %pad printk specifiers to print size_t and dma_addr_t variables, and cast pointers to uintptr_t instead of unsigned int where applicable. This fixes warnings on platforms where pointers and/or dma_addr_t have a different size than int. Cc: linux-serial@vger.kernel.org Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-11serial: tegra: convert to standard DMA DT bindingsStephen Warren
By using dma_request_slave_channel_or_err(), the DMA slave ID can be looked up from standard DT properties, and squirrelled away during channel allocation. Hence, there's no need to use a custom DT property to store the slave ID. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Thierry Reding <treding@nvidia.com>
2013-12-11serial: tegra: use reset frameworkStephen Warren
Tegra's clock driver now provides an implementation of the common reset API (include/linux/reset.h). Use this instead of the old Tegra- specific API; that will soon be removed. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thierry Reding <treding@nvidia.com>
2013-12-09tty: Halve flip buffer GFP_ATOMIC memory consumptionPeter Hurley
tty flip buffers use GFP_ATOMIC allocations for received data which is to be processed by the line discipline. For each byte received, an extra byte is used to indicate the error status of that byte. Instead, if the received data is error-free, encode the entire buffer without status bytes. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: xuartps: Properly guard sysrq specific codeSoren Brinkmann
Commit 'tty: xuartps: Implement BREAK detection, add SYSRQ support' (0c0c47bc40a2e358d593b2d7fb93b50027fbfc0c) introduced sysrq support without properly guarding sysrq specific code which results in build errors when sysrq is disabled: DNAME=KBUILD_STR(xilinx_uartps)" -c -o drivers/tty/serial/.tmp_xilinx_uartps.o drivers/tty/serial/xilinx_uartps.c drivers/tty/serial/xilinx_uartps.c: In function 'xuartps_isr': drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port' has no member named 'sysrq' drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port' has no member named 'sysrq' drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port' has no member named 'sysrq' make[3]: *** [drivers/tty/serial/xilinx_uartps.o] Error 1 Reported-by: Masanari Iida <standby24x7@gmail.com> Cc: Vlad Lungu <vlad.lungu@windriver.com> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: 8250: Fix initialisation of Quatech cards with the AMCC PCI chipJonathan Woithe
Fix the initialisation of older Quatech serial cards which are fitted with the AMCC PCI Matchmaker interface chip. Signed-off-by: Jonathan Woithe (jwoithe@just42.net) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: icom: dereference after free in load_code()Dan Carpenter
We use "fw" in the next line after we release it. I've shifted the call to release_firmware() down a couple lines to fix this. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: 8250_dw: add new ACPI IDsMika Westerberg
Newer Intel PCHs with LPSS have the same Designware controllers than Haswell but ACPI IDs are different. Add these IDs to the driver list. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: serial: pch: don't crash if DMA enabled but not loadedSebastian Andrzej Siewior
if the DMA driver isn't loaded "on time" then we crash in the irq handler: | pch_uart 0000:02:0a.4: pch_request_dma:dma_request_channel FAILS(Tx) | BUG: unable to handle kernel NULL pointer dereference at (null) | IP: [<c0676ed9>] pch_uart_interrupt+0x739/0x940 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: samsung: move clock deactivation below uart registrationHeiko Stübner
Commit 60e93575476f (serial: samsung: enable clock before clearing pending interrupts during init) added handling of the controller clock during init. On most systems this clock is also one of the baud_clock sources and possibly used by the earlycon and thus already enabled by the bootloader. Therefore a gap exists between s3c24xx_serial_init_port disabling the clock and an attached console reenabling it, making the transition from earlycon to regular console possibly hang the system - as seen on my S3C2442 based Freerunner today. Therefore move the disabling of the clock from s3c24xx_serial_init_port below the uart port registration, effectively creating an overlap and keeping the clock running non-stop if the console wants to grab this port. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: serial: mxs-auart: Check the return value from clk_prepare_enable()Fabio Estevam
clk_prepare_enable() may fail, so let's check its return value and propagate it in the case of error. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: Fix stale tty_buffer_flush() commentPeter Hurley
Commit d7a68be4f265be10e24be931c257af30ca55566b, 'tty: Only perform flip buffer flush from tty_buffer_flush()', removed buffer flushing from flush_to_ldisc(). Fix function header comment which describes the former behavior. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pl010: Convert to modern PM opsUlf Hansson
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up the PM callbacks. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: remove DEFINE_PCI_DEVICE_TABLE macroJingoo Han
Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro is not preferred. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: imx: add support for loopback mode.Huang Shijie
Add the loopback mode support for imx uart driver. Signed-off-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pl011: use DMA RX polling by defaultLinus Walleij
Making DMA RX polling optional when DMA is on was just over-cautious: there is one single system in the kernel tree using this facility, Ux500 and after some testing I turned this on also for Ux500, which means it should simply be on by default if DMA is enabled. Cc: Jongsung Kim <neidhard.kim@lge.com> Cc: Chanho Min <chanho.min@lge.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pl011: Convert to modern PM opsUlf Hansson
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up the PM callbacks. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_gsm: race between ld close and gsmtty openChao Bi
ttyA has ld associated to n_gsm, when ttyA is closing, it triggers to release gsmttyB's ld data dlci[B], then race would happen if gsmttyB is opening in parallel. (Note: This patch set differs from previous set in that it uses mutex instead of spin lock to avoid race, so that it avoids sleeping in automic context) Here are race cases we found recently in test: CASE #1 ==================================================================== releasing dlci[B] race with gsmtty_install(gsmttyB), then panic in gsmtty_open(gsmttyB), as below: tty_release(ttyA) tty_open(gsmttyB) | | ----- gsmtty_install(gsmttyB) | | ----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B] tty_ldisc_release(ttyA) ----- | | gsm_dlci_release(dlci[B]) ----- | | gsm_dlci_free(dlci[B]) ----- | | ----- gsmtty_open(gsmttyB) gsmtty_open() { struct gsm_dlci *dlci = tty->driver_data; => here it uses dlci[B] ... } In gsmtty_open(gsmttyA), it uses dlci[B] which was release, so hit a panic. ===================================================================== CASE #2 ===================================================================== releasing dlci[0] race with gsmtty_install(gsmttyB), then panic in gsmtty_open(), as below: tty_release(ttyA) tty_open(gsmttyB) | | ----- gsmtty_install(gsmttyB) | | ----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B] | | ----- gsmtty_open(gsmttyB) fail | | ----- tty_release(gsmttyB) | | ----- gsmtty_close(gsmttyB) | | ----- gsmtty_detach_dlci(dlci[B]) | | ----- dlci_put(dlci[B]) | | tty_ldisc_release(ttyA) ----- | | gsm_dlci_release(dlci[0]) ----- | | gsm_dlci_free(dlci[0]) ----- | | ----- dlci_put(dlci[0]) In gsmtty_detach_dlci(dlci[B]), it tries to use dlci[0] which was released, then hit panic. ===================================================================== IMHO, n_gsm tty operations would refer released ldisc, as long as gsm_dlci_release() has chance to release ldisc data when some gsmtty operations are ongoing.. This patch is try to avoid it by: 1) in n_gsm driver, use a global gsm mutex lock to avoid gsm_dlci_release() run in parallel with gsmtty_install(); 2) Increase dlci's ref count in gsmtty_install() instead of in gsmtty_open(), the purpose is to prevent gsm_dlci_release() releasing dlci after gsmtty_install() allocats dlci but before gsmtty_open increases dlci's ref count; 3) Decrease dlci's ref count in gsmtty_remove(), a tty framework API, this is the opposite process of step 2). Signed-off-by: Chao Bi <chao.bi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pch_uart: remove unnecessary pci_set_drvdata()Jingoo Han
The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08staging/fwserial: Rip out rx bufferingPeter Hurley
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: Remove tty_prepare_flip_string_flags()Peter Hurley
There is no in-tree user of tty_prepare_flip_string_flags(); remove. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: Rename tty buffer memory_used fieldPeter Hurley
Trim up the memory_used field name to mem_used. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: Enable configurable tty flip buffer limitPeter Hurley
Allow driver to configure its maximum flip buffer memory consumption/limit. This is necessary for very-high speed line rates (in excess of 10MB/sec) because the flip buffers can be saturated before the line discipline has a chance to throttle the input. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: Always handle NULL flag ptrPeter Hurley
Most line disciplines already handle the undocumented NULL flag ptr in their .receive_buf method; however, several don't. Document the NULL flag ptr, and correct handling in the N_MOUSE, N_GSM0710 and N_R394 line disciplines. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_tty: Only perform wakeups for waitersPeter Hurley
Only wakeup the _waiting_ reader, polls and/or writer(s). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_tty: Refactor input_available_p() by call sitePeter Hurley
Distinguish if caller is n_tty_poll() or n_tty_read(), and set the read/wakeup threshold accordingly. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_tty: Refactor PARMRK doubling checksPeter Hurley
Perform PARMRK doubling checks explicitly; remove ternary idiom and local variable. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_tty: Un-inline slow-path n_tty_receive_char_closing()Peter Hurley
Although n_tty_receive_char_closing() only has one call-site, let the compiler inline instead. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_tty: Un-inline slow-path n_tty_receive_char()Peter Hurley
Commit e60d27c4d8b33ba20896b76b6558f061bc6460ff, n_tty: Factor LNEXT processing from per-char i/o path, mistakenly inlined the non-inline alias, n_tty_receive_char(), for the inline function, n_tty_receive_char_inline(). As n_tty_receive_char() is intended for slow-path char processing only, un-inline it. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_tty: Merge .receive_buf() flavorsPeter Hurley
N_TTY's direct and flow-controlled flavors of the .receive_buf() method are nearly identical; fold together. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: pl011: remove redundant early amba_ports declarationBaruch Siach
This early amba_ports declaration was introduced by commit c16d51a32 (amba pl011: workaround for uart registers lockup) for use in the pl011_lockup_wa() routine. This routine was later removed by commit 4fd0690bb (serial: pl011: implement workaround for CTS clear event issue). Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial: 8250_dw: remove ACPI ifdefHeikki Krogerus
ACPI now provides stubs for the functions the driver uses. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08serial_core: Don't re-initialize a previously initialized spinlock.Randy Witt
The uart_set_options() code unconditionally initalizes the spinlock on the port. This can cause a deadlock in some situations. One instance that exposed the problem, was when writing to /sys/module/kgdboc/parameters/kgdboc to use ttyS0 when the console is already running on ttyS0. If the spinlock is re-initialized while the lock is held due to output to the console, there is a deadlock. Assume the spinlock is initialized if the port is a console. Signed-off-by: Randy Witt <rewitt@declaratino.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29n_tty: Fix missing newline echoPeter Hurley
When L_ECHONL is on, newlines are echoed regardless of the L_ECHO state; if set, ensure accumulated echoes are flushed before finishing the current input processing and before more output. Cc: <stable@vger.kernel.org> # 3.12.x Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25Revert "n_gsm: race between ld close and gsmtty open"Greg Kroah-Hartman
This reverts commit c284ee2cf12b55fa8496b2d098bf0938688f1c1c. Turns out the locking was incorrect. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Chao Bi <chao.bi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25n_tty: Protect minimum_to_wake reset for concurrent readersPeter Hurley
With multiple, concurrent readers (each waiting to acquire the atomic_read_lock mutex), a departing reader may mistakenly reset minimum_to_wake after a new reader has already set a new value. Protect the minimum_to_wake reset with the atomic_read_lock critical section. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25tty: Reset hupped state on openPeter Hurley
A common security idiom is to hangup the current tty (via vhangup()) after forking but before execing a root shell. This hangs up any existing opens which other processes may have and ensures subsequent opens have the necessary permissions to open the root shell tty/pty. Reset the TTY_HUPPED state after the driver has successfully returned the opened tty (perform the reset while the tty is locked to avoid racing with concurrent hangups). Reported-by: Heorhi Valakhanovich <valahanovich@tut.by> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> # 3.12 Tested-by: Heorhi Valakhanovich <valahanovich@tut.by> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25TTY: amiserial, add missing platform checkGeert Uytterhoeven
When booting a multi-platform m68k kernel on a non-Amiga with "console=ttyS0" on the kernel command line, it crashes with: Unable to handle kernel access at virtual address 81dff01c Oops: 00000000 PC: [<001e09a8>] serial_console_write+0xc/0x70 Add the missing platform check to amiserial_console_init() to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25TTY: pmac_zilog, check existence of ports in pmz_console_init()Geert Uytterhoeven
When booting a multi-platform m68k kernel on a non-Mac with "console=ttyS0" on the kernel command line, it crashes with: Unable to handle kernel NULL pointer dereference at virtual address (null) Oops: 00000000 PC: [<0013ad28>] __pmz_startup+0x32/0x2a0 ... Call Trace: [<002c5d3e>] pmz_console_setup+0x64/0xe4 The normal tty driver doesn't crash, because init_pmz() checks pmz_ports_count again after calling pmz_probe(). In the serial console initialization path, pmz_console_init() doesn't do this, causing the driver to crash later. Add a check for pmz_ports_count to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25n_gsm: race between ld close and gsmtty openChao Bi
ttyA has ld associated to n_gsm, when ttyA is closing, it triggers to release gsmttyB's ld data dlci[B], then race would happen if gsmttyB is opening in parallel. Here are race cases we found recently in test: CASE #1 ==================================================================== releasing dlci[B] race with gsmtty_install(gsmttyB), then panic in gsmtty_open(gsmttyB), as below: tty_release(ttyA) tty_open(gsmttyB) | | ----- gsmtty_install(gsmttyB) | | ----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B] tty_ldisc_release(ttyA) ----- | | gsm_dlci_release(dlci[B]) ----- | | gsm_dlci_free(dlci[B]) ----- | | ----- gsmtty_open(gsmttyB) gsmtty_open() { struct gsm_dlci *dlci = tty->driver_data; => here it uses dlci[B] ... } In gsmtty_open(gsmttyA), it uses dlci[B] which was release, so hit a panic. ===================================================================== CASE #2 ===================================================================== releasing dlci[0] race with gsmtty_install(gsmttyB), then panic in gsmtty_open(), as below: tty_release(ttyA) tty_open(gsmttyB) | | ----- gsmtty_install(gsmttyB) | | ----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B] | | ----- gsmtty_open(gsmttyB) fail | | ----- tty_release(gsmttyB) | | ----- gsmtty_close(gsmttyB) | | ----- gsmtty_detach_dlci(dlci[B]) | | ----- dlci_put(dlci[B]) | | tty_ldisc_release(ttyA) ----- | | gsm_dlci_release(dlci[0]) ----- | | gsm_dlci_free(dlci[0]) ----- | | ----- dlci_put(dlci[0]) In gsmtty_detach_dlci(dlci[B]), it tries to use dlci[0] which was released, then hit panic. ===================================================================== IMHO, n_gsm tty operations would refer released ldisc, as long as gsm_dlci_release() has chance to release ldisc data when some gsmtty operations are not completed.. This patch is try to avoid it by: 1) in n_gsm driver, use a global gsm spin lock to avoid gsm_dlci_release() run in parallel with gsmtty_install(); 2) Increase dlci's ref count in gsmtty_install() instead of in gsmtty_open(), the purpose is to prevent gsm_dlci_release() releasing dlci after gsmtty_install() allocats dlci but before gsmtty_open increases dlci's ref count; 3) Decrease dlci's ref count in gsmtty_remove(), which is a tty framework api, and this is the opposite process of step 2). Signed-off-by: Chao Bi <chao.bi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25tty/serial/8250: fix typo in help textRandy Dunlap
Commit 9326b047e4fd4a8da72e59d913214a1803e9709c includes a typo of "8350_core" instead of "8250_core", so correct it. Fixes kernel bugzilla #60724: https://bugzilla.kernel.org/show_bug.cgi?id=60724 Reported-by: Christoph Biedl <bugzilla.kernel.bpeb@manchmal.in-ulm.de> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25n_tty: Fix 4096-byte canonical readsPeter Hurley
Although the maximum allowable canonical line is specified to be 255 bytes (MAX_CANON), the practical limit has actually been the size of the line discipline read buffer (N_TTY_BUF_SIZE == 4096). Commit 32f13521ca68bc624ff6effc77f308a52b038bf0, n_tty: Line copy to user buffer in canonical mode, limited the line copy to 4095 bytes. With a completely full line discipline read buffer and a userspace buffer > 4095, _no_ data was copied, and the read() syscall returned 0, indicating EOF. Fix the interval arithmetic to compute the correct number of bytes to copy to userspace in the range [1..4096]. Cc: <stable@vger.kernel.org> # 3.12.x Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25n_tty: Fix echo overrun tail computationPeter Hurley
Commit cbfd0340ae1993378fd47179db949e050e16e697, 'n_tty: Process echoes in blocks', introduced an error when consuming the echo buffer tail to prevent buffer overrun, where the incorrect operation code byte is checked to determine how far to advance the tail to the next echo byte. Check the correct byte for the echo operation code byte. Cc: <stable@vger.kernel.org> # 3.12.x : c476f65 tty: incorrect test of echo_buf() result for ECHO_OP_START Cc: <stable@vger.kernel.org> # 3.12.x Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-25n_tty: Ensure reader restarts worker for next readerPeter Hurley
A departing reader must restart a flush_to_ldisc() worker _before_ the next reader enters the read loop; this is to avoid the new reader concluding no more i/o is available and prematurely exiting, when the old reader simply hasn't re-started the worker yet. Cc: stable <stable@vger.kernel.org> # 3.12 Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-20Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull slave-dmaengine changes from Vinod Koul: "This brings for slave dmaengine: - Change dma notification flag to DMA_COMPLETE from DMA_SUCCESS as dmaengine can only transfer and not verify validaty of dma transfers - Bunch of fixes across drivers: - cppi41 driver fixes from Daniel - 8 channel freescale dma engine support and updated bindings from Hongbo - msx-dma fixes and cleanup by Markus - DMAengine updates from Dan: - Bartlomiej and Dan finalized a rework of the dma address unmap implementation. - In the course of testing 1/ a collection of enhancements to dmatest fell out. Notably basic performance statistics, and fixed / enhanced test control through new module parameters 'run', 'wait', 'noverify', and 'verbose'. Thanks to Andriy and Linus [Walleij] for their review. - Testing the raid related corner cases of 1/ triggered bugs in the recently added 16-source operation support in the ioatdma driver. - Some minor fixes / cleanups to mv_xor and ioatdma" * 'next' of git://git.infradead.org/users/vkoul/slave-dma: (99 commits) dma: mv_xor: Fix mis-usage of mmio 'base' and 'high_base' registers dma: mv_xor: Remove unneeded NULL address check ioat: fix ioat3_irq_reinit ioat: kill msix_single_vector support raid6test: add new corner case for ioatdma driver ioatdma: clean up sed pool kmem_cache ioatdma: fix selection of 16 vs 8 source path ioatdma: fix sed pool selection ioatdma: Fix bug in selftest after removal of DMA_MEMSET. dmatest: verbose mode dmatest: convert to dmaengine_unmap_data dmatest: add a 'wait' parameter dmatest: add basic performance metrics dmatest: add support for skipping verification and random data setup dmatest: use pseudo random numbers dmatest: support xor-only, or pq-only channels in tests dmatest: restore ability to start test at module load and init dmatest: cleanup redundant "dmatest: " prefixes dmatest: replace stored results mechanism, with uniform messages Revert "dmatest: append verify result to results" ...
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