From: Sergei Shtylyov Date: Tue, 21 May 2013 19:07:54 +0000 (+0400) Subject: sata_rcar: clear STOP bit in bmdma_start() method X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=df7e131f6359f20ed8f0a37db039c4f6420a18c2;p=linux-beck.git sata_rcar: clear STOP bit in bmdma_start() method Iff bmdma_setup() has to stop a DMA transfer before starting a new one, then the STOP bit in the ATAPI_CONTROL1 register will remain set (it's only cleared when setting the START bit to 1) and then bmdma_start() method will set both START and STOP bits simultaneously which should abort the transfer being just started. Avoid that by explicitly clearing the STOP bit in bmdma_start() method (in this case it will be ignored on write). Signed-off-by: Sergei Shtylyov Signed-off-by: Tejun Heo Cc: stable@vger.kernel.org --- diff --git a/drivers/ata/sata_rcar.c b/drivers/ata/sata_rcar.c index 4799868bd733..a8e091aafdde 100644 --- a/drivers/ata/sata_rcar.c +++ b/drivers/ata/sata_rcar.c @@ -549,6 +549,7 @@ static void sata_rcar_bmdma_start(struct ata_queued_cmd *qc) /* start host DMA transaction */ dmactl = ioread32(priv->base + ATAPI_CONTROL1_REG); + dmactl &= ~ATAPI_CONTROL1_STOP; dmactl |= ATAPI_CONTROL1_START; iowrite32(dmactl, priv->base + ATAPI_CONTROL1_REG); }