From: Reimar Döffinger Reimar.Doeffinger@gmx.de
commit f971a85439bd25dc7b4d597cf5e4e8dc7ffc884b upstream.
Checking if DMA is enabled should be done via the ata_dma_enabled helper function, since the init state 0xff indicates disabled. This meant that ATA_CMD_READ_LOG_DMA_EXT was used and probed for before DMA was enabled, which caused hangs for some combinations of controllers and devices. It might also have caused it to be incorrectly disabled as broken, but there have been no reports of that.
Cc: stable@vger.kernel.org BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=195895 Signed-off-by: Reimar Döffinger Reimar.Doeffinger@gmx.de Tested-by: Paul Menzel pmenzel@molgen.mpg.de Signed-off-by: Damien Le Moal damien.lemoal@wdc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/ata/libata-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2073,7 +2073,7 @@ unsigned int ata_read_log_page(struct at
retry: ata_tf_init(dev, &tf); - if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id) && + if (ata_dma_enabled(dev) && ata_id_has_read_log_dma_ext(dev->id) && !(dev->horkage & ATA_HORKAGE_NO_DMA_LOG)) { tf.command = ATA_CMD_READ_LOG_DMA_EXT; tf.protocol = ATA_PROT_DMA;