This is a note to let you know that I've just added the patch titled dmaengine: idxd: Fix issues with PRS disable sysfs knob to the 6.4-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-issues-with-prs-disable-sysfs-kno.patch and it can be found in the queue-6.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0abc6409ffba65f0caf8d456db1f09e430240940 Author: Fenghua Yu <fenghua.yu@xxxxxxxxx> Date: Thu Aug 10 18:26:35 2023 -0700 dmaengine: idxd: Fix issues with PRS disable sysfs knob [ Upstream commit 8cae66574398326134a41513b419e00ad4e380ca ] There are two issues in the current PRS disable sysfs store function wq_prs_disable_store(): 1. Since PRS disable knob is invisible if PRS disable is not supported in WQ, it's redundant to check PRS support again in the store function again. Remove the redundant PRS support check. 2. Since PRS disable is read-only when the device is not configurable, PRS disable cannot be changed on the device. Add device configurable check in the store function. Fixes: f2dc327131b5 ("dmaengine: idxd: add per wq PRS disable") Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx> Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx> Link: https://lore.kernel.org/r/20230811012635.535413-2-fenghua.yu@xxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index 66c89b07b3f7b..a5c3eb4348325 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -1131,8 +1131,8 @@ static ssize_t wq_prs_disable_store(struct device *dev, struct device_attribute if (wq->state != IDXD_WQ_DISABLED) return -EPERM; - if (!idxd->hw.wq_cap.wq_prs_support) - return -EOPNOTSUPP; + if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) + return -EPERM; rc = kstrtobool(buf, &prs_dis); if (rc < 0)