From: Tom Rix trix@redhat.com
[ Upstream commit cdd296cdae1af2d27dae3fcfbdf12c5252ab78cf ]
Reviewing this block of code in cdv_intel_dp_init()
ret = cdv_intel_dp_aux_native_read(gma_encoder, DP_DPCD_REV, ...
cdv_intel_edp_panel_vdd_off(gma_encoder); if (ret == 0) { /* if this fails, presume the device is a ghost */ DRM_INFO("failed to retrieve link info, disabling eDP\n"); drm_encoder_cleanup(encoder); cdv_intel_dp_destroy(connector); goto err_priv; } else {
The (ret == 0) is not strict enough. cdv_intel_dp_aux_native_read() returns > 0 on success otherwise it is failure.
So change to <=
Fixes: d112a8163f83 ("gma500/cdv: Add eDP support")
Signed-off-by: Tom Rix trix@redhat.com Signed-off-by: Patrik Jakobsson patrik.r.jakobsson@gmail.com Link: https://patchwork.freedesktop.org/patch/msgid/20200805205911.20927-1-trix@re... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/gma500/cdv_intel_dp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/gma500/cdv_intel_dp.c b/drivers/gpu/drm/gma500/cdv_intel_dp.c index f41cbb753bb46..720a767118c9c 100644 --- a/drivers/gpu/drm/gma500/cdv_intel_dp.c +++ b/drivers/gpu/drm/gma500/cdv_intel_dp.c @@ -2078,7 +2078,7 @@ cdv_intel_dp_init(struct drm_device *dev, struct psb_intel_mode_device *mode_dev intel_dp->dpcd, sizeof(intel_dp->dpcd)); cdv_intel_edp_panel_vdd_off(gma_encoder); - if (ret == 0) { + if (ret <= 0) { /* if this fails, presume the device is a ghost */ DRM_INFO("failed to retrieve link info, disabling eDP\n"); drm_encoder_cleanup(encoder);