From 2eba08270990b99fb5429b76ee97184ddd272f7f Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 31 Mar 2009 20:14:58 +0200 Subject: [PATCH] ide-atapi: start DMA after issuing a packet command MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Apparently¹, some ATAPI devices want to see the packet command first before enabling DMA otherwise they simply hang indefinitely. Reorder the two steps and start DMA only after having issued the command first. [1] http://marc.info/?l=linux-kernel&m=123835520317235&w=2 Signed-off-by: Borislav Petkov Reported-by: Michael Roth Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/ide/ide-atapi.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c index d937e45..f591166 100644 --- a/drivers/ide/ide-atapi.c +++ b/drivers/ide/ide-atapi.c @@ -613,6 +613,10 @@ static ide_startstop_t ide_transfer_pc(ide_drive_t *drive) : ide_pc_intr), timeout); + /* Send the actual packet */ + if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0) + hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len); + /* Begin DMA, if necessary */ if (dev_is_idecd(drive)) { if (drive->dma) @@ -624,10 +628,6 @@ static ide_startstop_t ide_transfer_pc(ide_drive_t *drive) } } - /* Send the actual packet */ - if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0) - hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len); - return ide_started; } -- 2.7.4