dmaengine: idxd: check GENCAP config support for gencfg register

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>

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index cbbfa17d8d11bf9c8d0e5a8961177d906ab26b83..27612329f510738879bc3e100af03bc7535ee61e 100644 (file)
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -791,7 +791,7 @@ 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);