From: Borislav Petkov Date: Tue, 31 Mar 2009 18:14:58 +0000 (+0200) Subject: ide-atapi: start DMA after issuing a packet command X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=2eba08270990b99fb5429b76ee97184ddd272f7f;p=linux-2.6-omap-h63xx.git ide-atapi: start DMA after issuing a packet command 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 --- diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c index d937e45a677..f591166d2c9 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; }