ide: clear bmdma status in ide_intr() for ICHx controllers (revised #4)
patch 1/2 (revised):
- Fix drive->waiting_for_dma to work with CDB-intr devices.
- Do the dma status clearing in ide_intr() and add a new
hwif->ide_dma_clear_irq for Intel ICHx controllers.
Revised per Alan, Sergei and Bart's advice.
Patch against 2.6.20-rc6. Tested ok on my ICH4 and pdc20275 adapters.
Please review/apply, thanks.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "Adam W. Hawks" <awhawks@us.ibm.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 2614f41..99d1c43 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -1646,6 +1646,17 @@
del_timer(&hwgroup->timer);
spin_unlock(&ide_lock);
+ /* Some controllers might set DMA INTR no matter DMA or PIO;
+ * bmdma status might need to be cleared even for
+ * PIO interrupts to prevent spurious/lost irq.
+ */
+ if (hwif->ide_dma_clear_irq && !(drive->waiting_for_dma))
+ /* ide_dma_end() needs bmdma status for error checking.
+ * So, skip clearing bmdma status here and leave it
+ * to ide_dma_end() if this is dma interrupt.
+ */
+ hwif->ide_dma_clear_irq(drive);
+
if (drive->unmask)
local_irq_enable_in_hardirq();
/* service this interrupt, may set handler for next interrupt */