[PATCH] dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback

[PATCH] dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback

[Dave Jiang]

Current code blindly writes over the SWERR and the OVERFLOW bits. Write
back the bits actually read instead so the driver avoids clobbering the
OVERFLOW bit that comes after the register is read.

Fixes: bfe1d56091c1 ("dmaengine: idxd: Init and probe for Intel data accelerators")
Reported-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/dma/idxd/irq.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
index a60ca11a5784..f1463fc58112 100644
--- a/drivers/dma/idxd/irq.c
+++ b/drivers/dma/idxd/irq.c
@@ -124,7 +124,9 @@ static int process_misc_interrupts(struct idxd_device *idxd, u32 cause)
 		for (i = 0; i < 4; i++)
 			idxd->sw_err.bits[i] = ioread64(idxd->reg_base +
 					IDXD_SWERR_OFFSET + i * sizeof(u64));
-		iowrite64(IDXD_SWERR_ACK, idxd->reg_base + IDXD_SWERR_OFFSET);
+
+		iowrite64(idxd->sw_err.bits[0] & IDXD_SWERR_ACK,
+			  idxd->reg_base + IDXD_SWERR_OFFSET);
 
 		if (idxd->sw_err.valid && idxd->sw_err.wq_idx_valid) {
 			int id = idxd->sw_err.wq_idx;

Re: [PATCH] dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback

[Vinod Koul]

On 16-02-21, 17:13, Dave Jiang wrote:
> Current code blindly writes over the SWERR and the OVERFLOW bits. Write
> back the bits actually read instead so the driver avoids clobbering the
> OVERFLOW bit that comes after the register is read.

Applied, thanks

-- 
~Vinod