Albert Lee wrote:
patch 2/2 (revised):
- Do the dma status clearing in ide_intr() and add a new hwif->ide_dma_clear_irq such that LLDD can override it.
- Fix drive->waiting_for_dma to work with CDB-intr devices.
Signed-off-by: Albert Lee <albertcc@xxxxxxxxxx>
---
hwif->dma is not reliable: ide_intr() races with dma_start(). Sometimes we got hwif->dma == 0
in ide_intr() even though it is actually a DMA interrupt. So, drive->waiting_for_dma is used instead.
Also revised per Sergei's comments and let ide_dma_clear_irq return "void".
The "if (hwif->dma_status)" check in __ide_dma_clear_irq() is kept as is since I think
it would be safer for the old ISA/VESA IDE devices that has no BMDMA registers.
ISA/VESA drivers shouldn't have this method defined at all since they're
PIO only. But well, it won't hurt...
For your review, thanks.
diff -Nrup 01_remove_from_ide_cd/drivers/ide/ide-cd.c 02_add_to_ide_intr/drivers/ide/ide-cd.c
--- 01_remove_from_ide_cd/drivers/ide/ide-cd.c 2007-01-24 11:00:03.000000000 +0800
+++ 02_add_to_ide_intr/drivers/ide/ide-cd.c 2007-01-25 16:52:20.000000000 +0800
@@ -923,6 +923,10 @@ static ide_startstop_t cdrom_start_packe
HWIF(drive)->OUTB(drive->ctl, IDE_CONTROL_REG);
if (CDROM_CONFIG_FLAGS (drive)->drq_interrupt) {
+ /* waiting for CDB interrupt, not DMA yet. */
+ if (info->dma)
+ drive->waiting_for_dma = 0;
+
/* packet command */
ide_execute_command(drive, WIN_PACKETCMD, handler, ATAPI_WAIT_PC, cdrom_timer_expiry);
return ide_started;
@@ -965,6 +969,10 @@ static ide_startstop_t cdrom_transfer_pa
/* Check for errors. */
if (cdrom_decode_status(drive, DRQ_STAT, NULL))
return ide_stopped;
+
+ /* Ok, next interrupt will be dma interrupt. */
+ if (info->dma)
+ drive->waiting_for_dma = 1;
} else {
/* Otherwise, we must wait for DRQ to get set. */
if (ide_wait_stat(&startstop, drive, DRQ_STAT,
Erm... shouldn't we set drive->waiting_for_dma in hwif->dma_start() then?
Why it's set in hwif->dma_setup() at all I wonder?
MBR, Sergei
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