From: Borislav Petkov Date: Thu, 2 Apr 2009 20:21:31 +0000 (+0200) Subject: ide-atapi: start DMA after issuing a packet command X-Git-Tag: v2.6.29.2~73 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=717ff472176c54e90a4074898a59037f9a4791f5;p=thirdparty%2Fkernel%2Fstable.git ide-atapi: start DMA after issuing a packet command upstream commit: 2eba08270990b99fb5429b76ee97184ddd272f7f 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 Signed-off-by: Chris Wright --- diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c index 47497f8b4251e..53a9e8dd4e071 100644 --- a/drivers/ide/ide-atapi.c +++ b/drivers/ide/ide-atapi.c @@ -568,6 +568,10 @@ static ide_startstop_t ide_transfer_pc(ide_drive_t *drive) : ide_pc_intr), timeout, expiry); + /* 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) @@ -579,10 +583,6 @@ 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; }