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;