[PATCH 5.17 049/146] dmaengine: idxd: fix retry value to be constant for duration of function call

[Greg Kroah-Hartman]

From: Dave Jiang <dave.jiang@xxxxxxxxx>

[ Upstream commit bc3452cdfc468a65965d0ac397c940acb787ea4d ]

When retries is compared to wq->enqcmds_retries each loop of idxd_enqcmds(),
wq->enqcmds_retries can potentially changed by user. Assign the value
of retries to wq->enqcmds_retries during initialization so it is the
original value set when entering the function.

Fixes: 7930d8553575 ("dmaengine: idxd: add knob for enqcmds retries")
Suggested-by: Dave Hansen <dave.hansen@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://lore.kernel.org/r/165031760154.3658664.1983547716619266558.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/dma/idxd/submit.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
index 554b0602d2e9..c01db23e3333 100644
--- a/drivers/dma/idxd/submit.c
+++ b/drivers/dma/idxd/submit.c
@@ -150,7 +150,7 @@ static void llist_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie,
  */
 int idxd_enqcmds(struct idxd_wq *wq, void __iomem *portal, const void *desc)
 {
-	unsigned int retries = 0;
+	unsigned int retries = wq->enqcmds_retries;
 	int rc;
 
 	do {
@@ -158,7 +158,7 @@ int idxd_enqcmds(struct idxd_wq *wq, void __iomem *portal, const void *desc)
 		if (rc == 0)
 			break;
 		cpu_relax();
-	} while (retries++ < wq->enqcmds_retries);
+	} while (retries--);
 
 	return rc;
 }
-- 
2.35.1