From: AnilKumar Ch Date: Wed, 23 May 2012 12:15:10 +0000 (+0530) Subject: can: c_can: fix an interrupt thrash issue with c_can driver X-Git-Tag: v3.5-rc3~22^2~40^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=148c87c89e1a8863d3d965179f3ab1a06490569e;p=pandora-kernel.git 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 --- Reading git-diff-tree failed