This is a note to let you know that I've just added the patch titled
dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-idxd-fix-clobbering-of-swerr-overflow-bit-.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b478c93c33ddcd3798a8662732b33bf430a54107
Author: Dave Jiang <dave.jiang@xxxxxxxxx>
Date: Tue Feb 16 17:13:42 2021 -0700
dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback
[ 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 <sanjay.k.kumar@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://lore.kernel.org/r/161352082229.3511254.1002151220537623503.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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;
