[PATCH 2/2] dmaengine: idxd: Fix issues with PRS disable sysfs knob

[Fenghua Yu]

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>
---
Applied cleanly to
https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine next

 drivers/dma/idxd/sysfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 66c89b07b3f7..a5c3eb434832 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)
-- 
2.37.1