From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sergei Shtylyov , Tejun Heo Subject: [ 074/127] sata_rcar: clear STOP bit in bmdma_start() method Date: Wed, 5 Jun 2013 14:34:01 -0700 Message-Id: <20130605213226.358880887@linuxfoundation.org> In-Reply-To: <20130605213217.966891866@linuxfoundation.org> References: <20130605213217.966891866@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sergei Shtylyov commit df7e131f6359f20ed8f0a37db039c4f6420a18c2 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/ata/sata_rcar.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/ata/sata_rcar.c +++ b/drivers/ata/sata_rcar.c @@ -548,6 +548,7 @@ static void sata_rcar_bmdma_start(struct /* 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); }