| From | Greg Kroah-Hartman <> | Subject | [ 074/127] sata_rcar: clear STOP bit in bmdma_start() method | Date | Wed, 5 Jun 2013 14:34:01 -0700 |
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3.9-stable review patch. If anyone has any objections, please let me know.
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From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
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 <sergei.shtylyov@cogentembedded.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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); }
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