6.15-stable review patch. If anyone has any objections, please let me know.
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From: Aleksandrs Vinarskis alex.vinarskis@gmail.com
[ Upstream commit 7513ccb8840b54e35579f3c2cce08c3443a6e2d4 ]
Per-segment link training requires knowing the number of LTTPRs (if any) present. Store the count during LTTPRs' initialization.
Fixes: 72d0af4accd9 ("drm/msm/dp: Add support for LTTPR handling") Reviewed-by: Abel Vesa abel.vesa@linaro.org Reviewed-by: Abhinav Kumar quic_abhinavk@quicinc.com Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@oss.qualcomm.com Signed-off-by: Aleksandrs Vinarskis alex.vinarskis@gmail.com Tested-by: Jessica Zhang quic_jesszhan@quicinc.com # SA8775P Tested-by: Johan Hovold johan+linaro@kernel.org Tested-by: Rob Clark robdclark@gmail.com Patchwork: https://patchwork.freedesktop.org/patch/652306/ Link: https://lore.kernel.org/r/20250507230113.14270-4-alex.vinarskis@gmail.com Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@oss.qualcomm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/dp/dp_display.c | 17 +++++++++++------ drivers/gpu/drm/msm/dp/dp_link.h | 1 + 2 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 5c57c1d7ac601..ab8c1f19dcb42 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -367,16 +367,21 @@ static int msm_dp_display_send_hpd_notification(struct msm_dp_display_private *d return 0; }
-static void msm_dp_display_lttpr_init(struct msm_dp_display_private *dp, u8 *dpcd) +static int msm_dp_display_lttpr_init(struct msm_dp_display_private *dp, u8 *dpcd) { - int rc; + int rc, lttpr_count;
if (drm_dp_read_lttpr_common_caps(dp->aux, dpcd, dp->link->lttpr_common_caps)) - return; + return 0;
- rc = drm_dp_lttpr_init(dp->aux, drm_dp_lttpr_count(dp->link->lttpr_common_caps)); - if (rc) + lttpr_count = drm_dp_lttpr_count(dp->link->lttpr_common_caps); + rc = drm_dp_lttpr_init(dp->aux, lttpr_count); + if (rc) { DRM_ERROR("failed to set LTTPRs transparency mode, rc=%d\n", rc); + return 0; + } + + return lttpr_count; }
static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) @@ -390,7 +395,7 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) if (rc) goto end;
- msm_dp_display_lttpr_init(dp, dpcd); + dp->link->lttpr_count = msm_dp_display_lttpr_init(dp, dpcd);
rc = msm_dp_panel_read_sink_caps(dp->panel, connector); if (rc) diff --git a/drivers/gpu/drm/msm/dp/dp_link.h b/drivers/gpu/drm/msm/dp/dp_link.h index c47d75cfc720c..ba47c6d19fbfa 100644 --- a/drivers/gpu/drm/msm/dp/dp_link.h +++ b/drivers/gpu/drm/msm/dp/dp_link.h @@ -62,6 +62,7 @@ struct msm_dp_link_phy_params {
struct msm_dp_link { u8 lttpr_common_caps[DP_LTTPR_COMMON_CAP_SIZE]; + int lttpr_count;
u32 sink_request; u32 test_response;