From: Dave Jiang <[email protected]>

[ Upstream commit ea941ac294d75d0ace50797aebf0056f6f8f7a7f ]

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 <[email protected]>
Signed-off-by: Dave Jiang <[email protected]>
Link: 
https://lore.kernel.org/r/161352082229.3511254.1002151220537623503.st...@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 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;
-- 
2.30.2



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