[PATCH] dmaengine: idxd: check GENCAP config support for gencfg register

[Dave Jiang <dave.jiang@xxxxxxxxx>]

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>
---
 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 419b206f8a42..1e153725432e 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -793,7 +793,7 @@ 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);