| Message ID | 20240622110929.3115714-12-a-bhatia1@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: cdns-dsi: Fix the color-shift issue | expand |
On 22/06/2024 14:09, Aradhya Bhatia wrote: > The cdns-dsi controller requires that it be turned on completely before > the input DPI's source has begun streaming[0]. Not having that, allows > for a small window before cdns-dsi enable and after cdns-dsi disable > where the previous entity (in this case tidss's videoport) to continue > streaming DPI video signals. This small window where cdns-dsi is > disabled but is still receiving signals causes the input FIFO of > cdns-dsi to get corrupted. This causes the colors to shift on the output > display. The colors can either shift by one color component (R->G, G->B, > B->R), or by two color components (R->B, G->R, B->G). > > Since tidss's videoport starts streaming via crtc enable hooks, we need > cdns-dsi to be up and running before that. Now that the bridges are > pre_enabled before crtc is enabled, and post_disabled after crtc is > disabled, use the pre_enable and post_disable hooks to get cdns-dsi > ready and running before the tidss videoport to get pass the color shift > issues. > > [0]: See section 12.6.5.7.3 "Start-up Procedure" in J721E SoC TRM > TRM Link: http://www.ti.com/lit/pdf/spruil1 > I think it makes sense to explain a bit about this in a comment in the driver code. Otherwise doing all of this in pre_enable and post_disable looks a bit odd. Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Tomi > Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com> > --- > .../gpu/drm/bridge/cadence/cdns-dsi-core.c | 32 +++---------------- > 1 file changed, 4 insertions(+), 28 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c > index c9697818308e..c352ea7db4ed 100644 > --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c > +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c > @@ -655,8 +655,8 @@ cdns_dsi_bridge_mode_valid(struct drm_bridge *bridge, > return MODE_OK; > } > > -static void cdns_dsi_bridge_atomic_disable(struct drm_bridge *bridge, > - struct drm_bridge_state *old_bridge_state) > +static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge, > + struct drm_bridge_state *old_bridge_state) > { > struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); > struct cdns_dsi *dsi = input_to_dsi(input); > @@ -680,15 +680,6 @@ static void cdns_dsi_bridge_atomic_disable(struct drm_bridge *bridge, > pm_runtime_put(dsi->base.dev); > } > > -static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge, > - struct drm_bridge_state *old_bridge_state) > -{ > - struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); > - struct cdns_dsi *dsi = input_to_dsi(input); > - > - pm_runtime_put(dsi->base.dev); > -} > - > static void cdns_dsi_hs_init(struct cdns_dsi *dsi) > { > struct cdns_dsi_output *output = &dsi->output; > @@ -757,8 +748,8 @@ static void cdns_dsi_init_link(struct cdns_dsi *dsi) > dsi->link_initialized = true; > } > > -static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge, > - struct drm_bridge_state *old_bridge_state) > +static void cdns_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge, > + struct drm_bridge_state *old_bridge_state) > { > struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); > struct cdns_dsi *dsi = input_to_dsi(input); > @@ -909,19 +900,6 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge, > writel(tmp, dsi->regs + MCTL_MAIN_EN); > } > > -static void cdns_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge, > - struct drm_bridge_state *old_bridge_state) > -{ > - struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); > - struct cdns_dsi *dsi = input_to_dsi(input); > - > - if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0)) > - return; > - > - cdns_dsi_init_link(dsi); > - cdns_dsi_hs_init(dsi); > -} > - > static u32 *cdns_dsi_bridge_get_input_bus_fmts(struct drm_bridge *bridge, > struct drm_bridge_state *bridge_state, > struct drm_crtc_state *crtc_state, > @@ -952,9 +930,7 @@ static u32 *cdns_dsi_bridge_get_input_bus_fmts(struct drm_bridge *bridge, > static const struct drm_bridge_funcs cdns_dsi_bridge_funcs = { > .attach = cdns_dsi_bridge_attach, > .mode_valid = cdns_dsi_bridge_mode_valid, > - .atomic_disable = cdns_dsi_bridge_atomic_disable, > .atomic_pre_enable = cdns_dsi_bridge_atomic_pre_enable, > - .atomic_enable = cdns_dsi_bridge_atomic_enable, > .atomic_post_disable = cdns_dsi_bridge_atomic_post_disable, > .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, > .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index c9697818308e..c352ea7db4ed 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -655,8 +655,8 @@ cdns_dsi_bridge_mode_valid(struct drm_bridge *bridge, return MODE_OK; } -static void cdns_dsi_bridge_atomic_disable(struct drm_bridge *bridge, - struct drm_bridge_state *old_bridge_state) +static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) { struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); struct cdns_dsi *dsi = input_to_dsi(input); @@ -680,15 +680,6 @@ static void cdns_dsi_bridge_atomic_disable(struct drm_bridge *bridge, pm_runtime_put(dsi->base.dev); } -static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge, - struct drm_bridge_state *old_bridge_state) -{ - struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); - struct cdns_dsi *dsi = input_to_dsi(input); - - pm_runtime_put(dsi->base.dev); -} - static void cdns_dsi_hs_init(struct cdns_dsi *dsi) { struct cdns_dsi_output *output = &dsi->output; @@ -757,8 +748,8 @@ static void cdns_dsi_init_link(struct cdns_dsi *dsi) dsi->link_initialized = true; } -static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge, - struct drm_bridge_state *old_bridge_state) +static void cdns_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) { struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); struct cdns_dsi *dsi = input_to_dsi(input); @@ -909,19 +900,6 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge, writel(tmp, dsi->regs + MCTL_MAIN_EN); } -static void cdns_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge, - struct drm_bridge_state *old_bridge_state) -{ - struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); - struct cdns_dsi *dsi = input_to_dsi(input); - - if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0)) - return; - - cdns_dsi_init_link(dsi); - cdns_dsi_hs_init(dsi); -} - static u32 *cdns_dsi_bridge_get_input_bus_fmts(struct drm_bridge *bridge, struct drm_bridge_state *bridge_state, struct drm_crtc_state *crtc_state, @@ -952,9 +930,7 @@ static u32 *cdns_dsi_bridge_get_input_bus_fmts(struct drm_bridge *bridge, static const struct drm_bridge_funcs cdns_dsi_bridge_funcs = { .attach = cdns_dsi_bridge_attach, .mode_valid = cdns_dsi_bridge_mode_valid, - .atomic_disable = cdns_dsi_bridge_atomic_disable, .atomic_pre_enable = cdns_dsi_bridge_atomic_pre_enable, - .atomic_enable = cdns_dsi_bridge_atomic_enable, .atomic_post_disable = cdns_dsi_bridge_atomic_post_disable, .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
The cdns-dsi controller requires that it be turned on completely before the input DPI's source has begun streaming[0]. Not having that, allows for a small window before cdns-dsi enable and after cdns-dsi disable where the previous entity (in this case tidss's videoport) to continue streaming DPI video signals. This small window where cdns-dsi is disabled but is still receiving signals causes the input FIFO of cdns-dsi to get corrupted. This causes the colors to shift on the output display. The colors can either shift by one color component (R->G, G->B, B->R), or by two color components (R->B, G->R, B->G). Since tidss's videoport starts streaming via crtc enable hooks, we need cdns-dsi to be up and running before that. Now that the bridges are pre_enabled before crtc is enabled, and post_disabled after crtc is disabled, use the pre_enable and post_disable hooks to get cdns-dsi ready and running before the tidss videoport to get pass the color shift issues. [0]: See section 12.6.5.7.3 "Start-up Procedure" in J721E SoC TRM TRM Link: http://www.ti.com/lit/pdf/spruil1 Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com> --- .../gpu/drm/bridge/cadence/cdns-dsi-core.c | 32 +++---------------- 1 file changed, 4 insertions(+), 28 deletions(-)