From: Tejun Heo Date: Tue, 26 Jun 2007 17:48:43 +0000 (+0900) Subject: libata: use PIO for non-16 byte aligned ATAPI commands X-Git-Tag: v2.6.22-rc7~40^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b9a4197e266a40d5d1d16c9fb2a852cf10743afe;p=pandora-kernel.git libata: use PIO for non-16 byte aligned ATAPI commands The IDE driver used DMA for ATAPI commands if READ/WRITE command is multiple of sector size or sg command is multiple of 16 bytes. For libata, READ/WRITE sector alignment is guaranteed by the high level driver (sr), so we only have to worry about the 16 byte alignment. This patch makes ata_check_atapi_dma() always request PIO for all data transfer commands which are not multiple of 16 bytes. The following reports are related to this problem. http://bugzilla.kernel.org/show_bug.cgi?id=8605 (confirmed) http://thread.gmane.org/gmane.linux.kernel/476620 (confirmed) https://bugzilla.novell.com/show_bug.cgi?id=229260 (probably) Albert first pointed out the difference between IDE and libata. Kudos to him. Signed-off-by: Tejun Heo Cc: Albert Lee Signed-off-by: Jeff Garzik --- Reading git-diff-tree failed