From 148c87c89e1a8863d3d965179f3ab1a06490569e Mon Sep 17 00:00:00 2001 From: AnilKumar Ch Date: Wed, 23 May 2012 17:45:10 +0530 Subject: can: c_can: fix an interrupt thrash issue with c_can driver This patch fixes an interrupt thrash issue with c_can driver. In c_can_isr() function interrupts are disabled and enabled only in c_can_poll() function. c_can_isr() & c_can_poll() both read the irqstatus flag. However, irqstatus is always read as 0 in c_can_poll() because all C_CAN interrupts are disabled in c_can_isr(). This causes all interrupts to be re-enabled in c_can_poll() which in turn causes another interrupt since the event is not really handled. This keeps happening causing a flood of interrupts. To fix this, read the irqstatus register in isr and use the same cached value in the poll function. Cc: stable@kernel.org # 2.6.39+ Signed-off-by: AnilKumar Ch Acked-by: Wolfgang Grandegger Signed-off-by: Marc Kleine-Budde --- drivers/net/can/c_can/c_can.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/net/can/c_can/c_can.h') diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h index 9b7fbef3d09a..5f32d34af507 100644 --- a/drivers/net/can/c_can/c_can.h +++ b/drivers/net/can/c_can/c_can.h @@ -76,6 +76,7 @@ struct c_can_priv { unsigned int tx_next; unsigned int tx_echo; void *priv; /* for board-specific data */ + u16 irqstatus; }; struct net_device *alloc_c_can_dev(void); -- cgit