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authorAndiry Xu <andiry.xu@gmail.com>2012-06-13 10:51:57 +0800
committerSarah Sharp <sarah.a.sharp@linux.intel.com>2012-06-13 16:39:38 -0700
commit622eb783fe6ff4c1baa47db16c3a5db97f9e6e50 (patch)
tree1000c588770539c8e9781115bbd0d66f6bea1ec7 /drivers/usb
parent32f1d2c536d0c26c5814cb0e6a0606c42d02fac1 (diff)
xHCI: Increase the timeout for controller save/restore state operation
When system software decides to power down the xHC with the intent of resuming operation at a later time, it will ask xHC to save the internal state and restore it when resume to correctly recover from a power event. Two bits are used to enable this operation: Save State and Restore State. xHCI spec 4.23.2 says software should "Set the Controller Save/Restore State flag in the USBCMD register and wait for the Save/Restore State Status flag in the USBSTS register to transition to '0'". However, it does not define how long software should wait for the SSS/RSS bit to transition to 0. Currently the timeout is set to 1ms. There is bug report (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1002697) indicates that the timeout is too short for ASMedia ASM1042 host controller to save/restore the state successfully. Increase the timeout to 10ms helps to resolve the issue. This patch should be backported to stable kernels as old as 2.6.37, that contain the commit 5535b1d5f8885695c6ded783c692e3c0d0eda8ca "USB: xHCI: PCI power management implementation" Signed-off-by: Andiry Xu <andiry.xu@gmail.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Ming Lei <ming.lei@canonical.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/xhci.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 1d4958f7f00..a979cd0dbe0 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -795,8 +795,8 @@ int xhci_suspend(struct xhci_hcd *xhci)
command = xhci_readl(xhci, &xhci->op_regs->command);
command |= CMD_CSS;
xhci_writel(xhci, command, &xhci->op_regs->command);
- if (handshake(xhci, &xhci->op_regs->status, STS_SAVE, 0, 10*100)) {
- xhci_warn(xhci, "WARN: xHC CMD_CSS timeout\n");
+ if (handshake(xhci, &xhci->op_regs->status, STS_SAVE, 0, 10 * 1000)) {
+ xhci_warn(xhci, "WARN: xHC save state timeout\n");
spin_unlock_irq(&xhci->lock);
return -ETIMEDOUT;
}
@@ -848,8 +848,8 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
command |= CMD_CRS;
xhci_writel(xhci, command, &xhci->op_regs->command);
if (handshake(xhci, &xhci->op_regs->status,
- STS_RESTORE, 0, 10*100)) {
- xhci_dbg(xhci, "WARN: xHC CMD_CSS timeout\n");
+ STS_RESTORE, 0, 10 * 1000)) {
+ xhci_warn(xhci, "WARN: xHC restore state timeout\n");
spin_unlock_irq(&xhci->lock);
return -ETIMEDOUT;
}