| Message ID | 1704917931-30133-1-git-send-email-quic_khsieh@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v1] drm/msms/dp: fixed link clock divider bits be over written in BPC unknown case | expand |
On 1/10/2024 12:18 PM, Kuogee Hsieh wrote: > Since the value of DP_TEST_BIT_DEPTH_8 is already left shifted, in the > BPC unknown case, the additional shift causes spill over to the other > bits of the [DP_CONFIGURATION_CTRL] register. > Fix this by changing the return value of dp_link_get_test_bits_depth() > in the BPC unknown case to (DP_TEST_BIT_DEPTH_8 >> DP_TEST_BIT_DEPTH_SHIFT). > > Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> > --- > drivers/gpu/drm/msm/dp/dp_ctrl.c | 5 ----- > drivers/gpu/drm/msm/dp/dp_link.c | 10 +++++++--- > 2 files changed, 7 insertions(+), 8 deletions(-) > Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
On Wed, 10 Jan 2024 at 22:19, Kuogee Hsieh <quic_khsieh@quicinc.com> wrote: > > Since the value of DP_TEST_BIT_DEPTH_8 is already left shifted, in the > BPC unknown case, the additional shift causes spill over to the other > bits of the [DP_CONFIGURATION_CTRL] register. > Fix this by changing the return value of dp_link_get_test_bits_depth() > in the BPC unknown case to (DP_TEST_BIT_DEPTH_8 >> DP_TEST_BIT_DEPTH_SHIFT). > > Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> For the patch itself: Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Additional note. Since this made me look at how DP_TEST_BIT_DEPTH is handled in the driver, I stumbled upon dp_link_bit_depth_to_bpc() vs dp_link_bit_depth_to_bpp(). These two functions look pretty redundant. Since the former one is used only for the debugfs, please consider sending a patch that removes it for the sake of using the latter one and /3 in dp_test_data_show().
On 1/10/2024 12:18 PM, Kuogee Hsieh wrote: > Since the value of DP_TEST_BIT_DEPTH_8 is already left shifted, in the > BPC unknown case, the additional shift causes spill over to the other > bits of the [DP_CONFIGURATION_CTRL] register. > Fix this by changing the return value of dp_link_get_test_bits_depth() > in the BPC unknown case to (DP_TEST_BIT_DEPTH_8 >> DP_TEST_BIT_DEPTH_SHIFT). > > Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> > --- > drivers/gpu/drm/msm/dp/dp_ctrl.c | 5 ----- > drivers/gpu/drm/msm/dp/dp_link.c | 10 +++++++--- > 2 files changed, 7 insertions(+), 8 deletions(-) > Checkpatch complained about this error: CHECK: Alignment should match open parenthesis #61: FILE: drivers/gpu/drm/msm/dp/dp_link.c:1203: + drm_dbg_dp(link->drm_dev, "bpp=%d not supported, use bpc=8\n", + bpp); I will fix it while applying ... no need to spin another version for this.
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 77a8d93..fb588fd 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -135,11 +135,6 @@ static void dp_ctrl_config_ctrl(struct dp_ctrl_private *ctrl) tbd = dp_link_get_test_bits_depth(ctrl->link, ctrl->panel->dp_mode.bpp); - if (tbd == DP_TEST_BIT_DEPTH_UNKNOWN) { - pr_debug("BIT_DEPTH not set. Configure default\n"); - tbd = DP_TEST_BIT_DEPTH_8; - } - config |= tbd << DP_CONFIGURATION_CTRL_BPC_SHIFT; /* Num of Lanes */ diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c index 98427d4..b8caa5b 100644 --- a/drivers/gpu/drm/msm/dp/dp_link.c +++ b/drivers/gpu/drm/msm/dp/dp_link.c @@ -1179,6 +1179,9 @@ void dp_link_reset_phy_params_vx_px(struct dp_link *dp_link) u32 dp_link_get_test_bits_depth(struct dp_link *dp_link, u32 bpp) { u32 tbd; + struct dp_link_private *link; + + link = container_of(dp_link, struct dp_link_private, dp_link); /* * Few simplistic rules and assumptions made here: @@ -1196,12 +1199,13 @@ u32 dp_link_get_test_bits_depth(struct dp_link *dp_link, u32 bpp) tbd = DP_TEST_BIT_DEPTH_10; break; default: - tbd = DP_TEST_BIT_DEPTH_UNKNOWN; + drm_dbg_dp(link->drm_dev, "bpp=%d not supported, use bpc=8\n", + bpp); + tbd = DP_TEST_BIT_DEPTH_8; break; } - if (tbd != DP_TEST_BIT_DEPTH_UNKNOWN) - tbd = (tbd >> DP_TEST_BIT_DEPTH_SHIFT); + tbd = (tbd >> DP_TEST_BIT_DEPTH_SHIFT); return tbd; }
Since the value of DP_TEST_BIT_DEPTH_8 is already left shifted, in the BPC unknown case, the additional shift causes spill over to the other bits of the [DP_CONFIGURATION_CTRL] register. Fix this by changing the return value of dp_link_get_test_bits_depth() in the BPC unknown case to (DP_TEST_BIT_DEPTH_8 >> DP_TEST_BIT_DEPTH_SHIFT). Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 5 ----- drivers/gpu/drm/msm/dp/dp_link.c | 10 +++++++--- 2 files changed, 7 insertions(+), 8 deletions(-)