[PATCH 5.15 589/913] dmaengine: idxd: check GENCAP config support for gencfg register

[Greg Kroah-Hartman]

From: Dave Jiang <dave.jiang@xxxxxxxxx>

[ Upstream commit 79c4c3db7d86b9bec94562275efc82e58f3d0132 ]

DSA spec 1.2 has moved the GENCFG register under the GENCAP configuration
support with respect to writability. Add check in driver before writing to
GENCFG register.

Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://lore.kernel.org/r/163406171896.1303830.11217958011385656998.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/dma/idxd/device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index b468ca36d3a0..3cda1c5faf3c 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -801,7 +801,7 @@ static int idxd_groups_config_write(struct idxd_device *idxd)
 	struct device *dev = &idxd->pdev->dev;
 
 	/* Setup bandwidth token limit */
-	if (idxd->token_limit) {
+	if (idxd->hw.gen_cap.config_en && idxd->token_limit) {
 		reg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
 		reg.token_limit = idxd->token_limit;
 		iowrite32(reg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
-- 
2.34.1