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| author | Arnd Bergmann <arnd@arndb.de> | 2010-09-14 09:35:04 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-09-15 19:29:55 -0700 |
| commit | 72250d44bc76d3d7fa9253aeeb063a467e2458fa (patch) | |
| tree | 55e926467b3bc7a50e213c357e295225457072ff /drivers/isdn | |
| parent | 0a5f1d476aef43916abb2b8634ebff23ef2c05f6 (diff) | |
| download | linux-72250d44bc76d3d7fa9253aeeb063a467e2458fa.tar.gz linux-72250d44bc76d3d7fa9253aeeb063a467e2458fa.tar.bz2 linux-72250d44bc76d3d7fa9253aeeb063a467e2458fa.zip | |
i4l: kill big kernel lock
The isdn4linux driver uses the big kernel lock only
to serialize access to a few fields in its own
modem_info structure.
The easiest replacement is a driver-wide mutex.
More fine-grained locking would be more appropriate
here, but likely harder to implement.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/isdn')
| -rw-r--r-- | drivers/isdn/i4l/isdn_tty.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c index f013ee15327c..c463162843ba 100644 --- a/drivers/isdn/i4l/isdn_tty.c +++ b/drivers/isdn/i4l/isdn_tty.c @@ -14,7 +14,7 @@ #include <linux/isdn.h> #include <linux/slab.h> #include <linux/delay.h> -#include <linux/smp_lock.h> +#include <linux/mutex.h> #include "isdn_common.h" #include "isdn_tty.h" #ifdef CONFIG_ISDN_AUDIO @@ -28,6 +28,7 @@ /* Prototypes */ +static DEFINE_MUTEX(modem_info_mutex); static int isdn_tty_edit_at(const char *, int, modem_info *); static void isdn_tty_check_esc(const u_char *, u_char, int, int *, u_long *); static void isdn_tty_modem_reset_regs(modem_info *, int); @@ -1354,14 +1355,14 @@ isdn_tty_tiocmget(struct tty_struct *tty, struct file *file) if (tty->flags & (1 << TTY_IO_ERROR)) return -EIO; - lock_kernel(); + mutex_lock(&modem_info_mutex); #ifdef ISDN_DEBUG_MODEM_IOCTL printk(KERN_DEBUG "ttyI%d ioctl TIOCMGET\n", info->line); #endif control = info->mcr; status = info->msr; - unlock_kernel(); + mutex_unlock(&modem_info_mutex); return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) | ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) | ((status & UART_MSR_DCD) ? TIOCM_CAR : 0) @@ -1385,7 +1386,7 @@ isdn_tty_tiocmset(struct tty_struct *tty, struct file *file, printk(KERN_DEBUG "ttyI%d ioctl TIOCMxxx: %x %x\n", info->line, set, clear); #endif - lock_kernel(); + mutex_lock(&modem_info_mutex); if (set & TIOCM_RTS) info->mcr |= UART_MCR_RTS; if (set & TIOCM_DTR) { @@ -1407,7 +1408,7 @@ isdn_tty_tiocmset(struct tty_struct *tty, struct file *file, isdn_tty_modem_hup(info, 1); } } - unlock_kernel(); + mutex_unlock(&modem_info_mutex); return 0; } |