dmaengine: idxd: check GENCAP config support for gencfg register

[ 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@intel.com>
Link: https://lore.kernel.org/r/163406171896.1303830.11217958011385656998.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index b468ca3..3cda1c5 100644 (file)
--- 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);