Messages in this thread Patch in this message | | | Date | Mon, 14 Jul 2008 11:49:55 +0900 | From | Akinobu Mita <> | Subject | [PATCH] ip2: avoid add_timer() with pending timer |
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add_timer() is not suppose to be called when the timer is pending. ip2 driver attempts to avoid that condition by setting and resetting a flag (TimerOn) in timer function. But there is some gap between add_timer() and setting TimerOn.
This patch fix this problem by using mod_timer() and remove TimerOn which has been unnecessary by this change.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Michael H. Warfield <mhw@wittsend.com> --- drivers/char/ip2/ip2main.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-)
Index: 2.6-mmotm/drivers/char/ip2/ip2main.c =================================================================== --- 2.6-mmotm.orig/drivers/char/ip2/ip2main.c +++ 2.6-mmotm/drivers/char/ip2/ip2main.c @@ -252,7 +252,6 @@ static unsigned long bh_counter = 0; */ #define POLL_TIMEOUT (jiffies + 1) static DEFINE_TIMER(PollTimer, ip2_poll, 0, 0); -static char TimerOn; #ifdef IP2DEBUG_TRACE /* Trace (debug) buffer data */ @@ -372,10 +371,7 @@ ip2_cleanup_module(void) printk (KERN_DEBUG "Unloading %s: version %s\n", pcName, pcVersion ); #endif /* Stop poll timer if we had one. */ - if ( TimerOn ) { - del_timer ( &PollTimer ); - TimerOn = 0; - } + del_timer_sync(&PollTimer); /* Reset the boards we have. */ for( i = 0; i < IP2_MAX_BOARDS; ++i ) { @@ -746,10 +742,8 @@ ip2_loadmain(int *iop, int *irqp) } if ( ip2config.irq[i] == CIR_POLL ) { retry: - if (!TimerOn) { - PollTimer.expires = POLL_TIMEOUT; - add_timer ( &PollTimer ); - TimerOn = 1; + if (!timer_pending(&PollTimer)) { + mod_timer(&PollTimer, POLL_TIMEOUT); printk( KERN_INFO "IP2: polling\n"); } } else { @@ -1250,16 +1244,12 @@ ip2_poll(unsigned long arg) { ip2trace (ITRC_NO_PORT, ITRC_INTR, 100, 0 ); - TimerOn = 0; // it's the truth but not checked in service - // Just polled boards, IRQ = 0 will hit all non-interrupt boards. // It will NOT poll boards handled by hard interrupts. // The issue of queued BH interrupts is handled in ip2_interrupt(). ip2_polled_interrupt(); - PollTimer.expires = POLL_TIMEOUT; - add_timer( &PollTimer ); - TimerOn = 1; + mod_timer(&PollTimer, POLL_TIMEOUT); ip2trace (ITRC_NO_PORT, ITRC_INTR, ITRC_RETURN, 0 ); }
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