iwlwifi: software w/a for h/w bug cause Rx bit get clear

This is a w/a for a hardware bug. the h/w bug may cause the Rx bit
(bit 15 before shifting it to 31) to clear when using interrupt coalescing.

This does not mean frames are lost - their processing is just delayed until
next interrupt arrives.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Wey-Yi Guy 2010-01-15 13:43:38 -08:00 committed by John W. Linville
parent 2be76703a3
commit 2a11df6ee5
1 changed files with 10 additions and 0 deletions

View File

@ -1803,6 +1803,16 @@ irqreturn_t iwl_isr_ict(int irq, void *data)
if (val == 0xffffffff) if (val == 0xffffffff)
val = 0; val = 0;
/*
* this is a w/a for a h/w bug. the h/w bug may cause the Rx bit
* (bit 15 before shifting it to 31) to clear when using interrupt
* coalescing. fortunately, bits 18 and 19 stay set when this happens
* so we use them to decide on the real state of the Rx bit.
* In order words, bit 15 is set if bit 18 or bit 19 are set.
*/
if (val & 0xC0000)
val |= 0x8000;
inta = (0xff & val) | ((0xff00 & val) << 16); inta = (0xff & val) | ((0xff00 & val) << 16);
IWL_DEBUG_ISR(priv, "ISR inta 0x%08x, enabled 0x%08x ict 0x%08x\n", IWL_DEBUG_ISR(priv, "ISR inta 0x%08x, enabled 0x%08x ict 0x%08x\n",
inta, inta_mask, val); inta, inta_mask, val);