drm/msm/dsi: Fix return value check for clk_get_parent

commit 5fb9b797d5ccf311ae4aba69e86080d47668b5f7 upstream.

clk_get_parent returns an error pointer upon failure, not NULL. So the
checks as they exist won't catch a failure. This patch changes the
checks and the return values to properly handle an error pointer.

Fixes: c4d8cfe516dc ("drm/msm/dsi: add implementation for helper functions")
Cc: Sibi Sankar <sibis@codeaurora.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Rob Clark <robdclark@chromium.org>
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 96fb5f6..cc4ea55 100644 (file)
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -429,15 +429,15 @@ static int dsi_clk_init(struct msm_dsi_host *msm_host)
        }
 
        msm_host->byte_clk_src = clk_get_parent(msm_host->byte_clk);
-       if (!msm_host->byte_clk_src) {
-               ret = -ENODEV;
+       if (IS_ERR(msm_host->byte_clk_src)) {
+               ret = PTR_ERR(msm_host->byte_clk_src);
                pr_err("%s: can't find byte_clk clock. ret=%d\n", __func__, ret);
                goto exit;
        }
 
        msm_host->pixel_clk_src = clk_get_parent(msm_host->pixel_clk);
-       if (!msm_host->pixel_clk_src) {
-               ret = -ENODEV;
+       if (IS_ERR(msm_host->pixel_clk_src)) {
+               ret = PTR_ERR(msm_host->pixel_clk_src);
                pr_err("%s: can't find pixel_clk clock. ret=%d\n", __func__, ret);
                goto exit;
        }