diff options
Diffstat (limited to 'drivers/char/generic_serial.c')
| -rw-r--r-- | drivers/char/generic_serial.c | 120 |
1 files changed, 3 insertions, 117 deletions
diff --git a/drivers/char/generic_serial.c b/drivers/char/generic_serial.c index 8ea02755b1c..8facf3e25c4 100644 --- a/drivers/char/generic_serial.c +++ b/drivers/char/generic_serial.c @@ -43,16 +43,6 @@ static int gs_debug; #define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter %s\n", __FUNCTION__) #define func_exit() gs_dprintk (GS_DEBUG_FLOW, "gs: exit %s\n", __FUNCTION__) -#define NEW_WRITE_LOCKING 1 -#if NEW_WRITE_LOCKING -#define DECL /* Nothing */ -#define LOCKIT mutex_lock(& port->port_write_mutex); -#define RELEASEIT mutex_unlock(&port->port_write_mutex); -#else -#define DECL unsigned long flags; -#define LOCKIT save_flags (flags);cli () -#define RELEASEIT restore_flags (flags) -#endif #define RS_EVENT_WRITE_WAKEUP 1 @@ -62,7 +52,6 @@ module_param(gs_debug, int, 0644); void gs_put_char(struct tty_struct * tty, unsigned char ch) { struct gs_port *port; - DECL func_enter (); @@ -75,11 +64,11 @@ void gs_put_char(struct tty_struct * tty, unsigned char ch) if (! (port->flags & ASYNC_INITIALIZED)) return; /* Take a lock on the serial tranmit buffer! */ - LOCKIT; + mutex_lock(& port->port_write_mutex); if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) { /* Sorry, buffer is full, drop character. Update statistics???? -- REW */ - RELEASEIT; + mutex_unlock(&port->port_write_mutex); return; } @@ -87,13 +76,11 @@ void gs_put_char(struct tty_struct * tty, unsigned char ch) port->xmit_head &= SERIAL_XMIT_SIZE - 1; port->xmit_cnt++; /* Characters in buffer */ - RELEASEIT; + mutex_unlock(&port->port_write_mutex); func_exit (); } -#ifdef NEW_WRITE_LOCKING - /* > Problems to take into account are: > -1- Interrupts that empty part of the buffer. @@ -166,90 +153,6 @@ int gs_write(struct tty_struct * tty, func_exit (); return total; } -#else -/* -> Problems to take into account are: -> -1- Interrupts that empty part of the buffer. -> -2- page faults on the access to userspace. -> -3- Other processes that are also trying to do a "write". -*/ - -int gs_write(struct tty_struct * tty, - const unsigned char *buf, int count) -{ - struct gs_port *port; - int c, total = 0; - int t; - unsigned long flags; - - func_enter (); - - /* The standard serial driver returns 0 in this case. - That sounds to me as "No error, I just didn't get to writing any - bytes. Feel free to try again." - The "official" way to write n bytes from buf is: - - for (nwritten = 0;nwritten < n;nwritten += rv) { - rv = write (fd, buf+nwritten, n-nwritten); - if (rv < 0) break; // Error: bail out. // - } - - which will loop endlessly in this case. The manual page for write - agrees with me. In practise almost everybody writes - "write (fd, buf,n);" but some people might have had to deal with - incomplete writes in the past and correctly implemented it by now... - */ - - if (!tty) return -EIO; - - port = tty->driver_data; - if (!port || !port->xmit_buf) - return -EIO; - - local_save_flags(flags); - while (1) { - cli(); - c = count; - - /* This is safe because we "OWN" the "head". Noone else can - change the "head": we own the port_write_mutex. */ - /* Don't overrun the end of the buffer */ - t = SERIAL_XMIT_SIZE - port->xmit_head; - if (t < c) c = t; - - /* This is safe because the xmit_cnt can only decrease. This - would increase "t", so we might copy too little chars. */ - /* Don't copy past the "head" of the buffer */ - t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt; - if (t < c) c = t; - - /* Can't copy more? break out! */ - if (c <= 0) { - local_restore_flags(flags); - break; - } - memcpy(port->xmit_buf + port->xmit_head, buf, c); - port->xmit_head = ((port->xmit_head + c) & - (SERIAL_XMIT_SIZE-1)); - port->xmit_cnt += c; - local_restore_flags(flags); - buf += c; - count -= c; - total += c; - } - - if (port->xmit_cnt && - !tty->stopped && - !tty->hw_stopped && - !(port->flags & GS_TX_INTEN)) { - port->flags |= GS_TX_INTEN; - port->rd->enable_tx_interrupts (port); - } - func_exit (); - return total; -} - -#endif @@ -737,23 +640,6 @@ void gs_set_termios (struct tty_struct * tty, gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp); } - /* This is an optimization that is only allowed for dumb cards */ - /* Smart cards require knowledge of iflags and oflags too: that - might change hardware cooking mode.... */ - if (old_termios) { - if( (tiosp->c_iflag == old_termios->c_iflag) - && (tiosp->c_oflag == old_termios->c_oflag) - && (tiosp->c_cflag == old_termios->c_cflag) - && (tiosp->c_lflag == old_termios->c_lflag) - && (tiosp->c_line == old_termios->c_line) - && (memcmp(tiosp->c_cc, old_termios->c_cc, NCC) == 0)) { - gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: optimized away\n"); - return /* 0 */; - } - } else - gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: no old_termios: " - "no optimization\n"); - if(old_termios && (gs_debug & GS_DEBUG_TERMIOS)) { if(tiosp->c_iflag != old_termios->c_iflag) printk("c_iflag changed\n"); if(tiosp->c_oflag != old_termios->c_oflag) printk("c_oflag changed\n"); |