6.18-stable review patch. If anyone has any objections, please let me know.
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From: Jayesh Choudhary j-choudhary@ti.com
[ Upstream commit 86db652fc22f5674ffe3b1f7c91c397c69d26d94 ]
After integrating OLDI support[0], it is necessary to identify which VP instances use OLDI, since the OLDI driver owns the video port clock (as a serial clock). Clock operations on these VPs must be delegated to the OLDI driver, not handled by the TIDSS driver. This issue also emerged in upstream discussions when DSI-related clock management was attempted in the TIDSS driver[1].
To address this, add an 'is_ext_vp_clk' array to the 'tidss_device' structure, marking a VP as 'true' during 'tidss_oldi_init()' and as 'false' during 'tidss_oldi_deinit()'. TIDSS then uses 'is_ext_vp_clk' to skip clock validation checks in 'dispc_vp_mode_valid()' for VPs under OLDI control.
Since OLDI uses the DSS VP clock directly as a serial interface and manages its own rate, mode validation should be implemented in the OLDI bridge's 'mode_valid' hook. This patch adds that logic, ensuring proper delegation and avoiding spurious clock handling in the TIDSS driver.
[0]: https://lore.kernel.org/all/20250528122544.817829-1-aradhya.bhatia@linux.dev... [1]: https://lore.kernel.org/all/DA6TT575Z82D.3MPK8HG5GRL8U@kernel.org/
Fixes: 7246e0929945 ("drm/tidss: Add OLDI bridge support") Tested-by: Michael Walle mwalle@kernel.org Reviewed-by: Devarsh Thakkar devarsht@ti.com Reviewed-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com Signed-off-by: Jayesh Choudhary j-choudhary@ti.com Signed-off-by: Swamil Jain s-jain1@ti.com Link: https://patch.msgid.link/20251104151422.307162-3-s-jain1@ti.com Signed-off-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com Link: https://patch.msgid.link/ffd5ebe03391b3c01e616c0c844a4b8ddecede36.1762513240... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/tidss/tidss_dispc.c | 7 +++++++ drivers/gpu/drm/tidss/tidss_drv.h | 2 ++ drivers/gpu/drm/tidss/tidss_oldi.c | 22 ++++++++++++++++++++++ 3 files changed, 31 insertions(+)
diff --git a/drivers/gpu/drm/tidss/tidss_dispc.c b/drivers/gpu/drm/tidss/tidss_dispc.c index 55259b8e87510..6bf1171d0bc2d 100644 --- a/drivers/gpu/drm/tidss/tidss_dispc.c +++ b/drivers/gpu/drm/tidss/tidss_dispc.c @@ -1313,6 +1313,13 @@ static int check_pixel_clock(struct dispc_device *dispc, u32 hw_videoport, { unsigned long round_clock;
+ /* + * For VP's with external clocking, clock operations must be + * delegated to respective driver, so we skip the check here. + */ + if (dispc->tidss->is_ext_vp_clk[hw_videoport]) + return 0; + round_clock = clk_round_rate(dispc->vp_clk[hw_videoport], clock); /* * To keep the check consistent with dispc_vp_set_clk_rate(), we diff --git a/drivers/gpu/drm/tidss/tidss_drv.h b/drivers/gpu/drm/tidss/tidss_drv.h index 84454a4855d11..e1c1f41d8b4be 100644 --- a/drivers/gpu/drm/tidss/tidss_drv.h +++ b/drivers/gpu/drm/tidss/tidss_drv.h @@ -24,6 +24,8 @@ struct tidss_device {
const struct dispc_features *feat; struct dispc_device *dispc; + bool is_ext_vp_clk[TIDSS_MAX_PORTS]; +
unsigned int num_crtcs; struct drm_crtc *crtcs[TIDSS_MAX_PORTS]; diff --git a/drivers/gpu/drm/tidss/tidss_oldi.c b/drivers/gpu/drm/tidss/tidss_oldi.c index 7688251beba28..17c535bfa0576 100644 --- a/drivers/gpu/drm/tidss/tidss_oldi.c +++ b/drivers/gpu/drm/tidss/tidss_oldi.c @@ -309,6 +309,25 @@ static u32 *tidss_oldi_atomic_get_input_bus_fmts(struct drm_bridge *bridge, return input_fmts; }
+static enum drm_mode_status +tidss_oldi_mode_valid(struct drm_bridge *bridge, + const struct drm_display_info *info, + const struct drm_display_mode *mode) +{ + struct tidss_oldi *oldi = drm_bridge_to_tidss_oldi(bridge); + unsigned long round_clock; + + round_clock = clk_round_rate(oldi->serial, mode->clock * 7 * 1000); + /* + * To keep the check consistent with dispc_vp_set_clk_rate(), + * we use the same 5% check here. + */ + if (dispc_pclk_diff(mode->clock * 7 * 1000, round_clock) > 5) + return -EINVAL; + + return 0; +} + static const struct drm_bridge_funcs tidss_oldi_bridge_funcs = { .attach = tidss_oldi_bridge_attach, .atomic_pre_enable = tidss_oldi_atomic_pre_enable, @@ -317,6 +336,7 @@ static const struct drm_bridge_funcs tidss_oldi_bridge_funcs = { .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, .atomic_reset = drm_atomic_helper_bridge_reset, + .mode_valid = tidss_oldi_mode_valid, };
static int get_oldi_mode(struct device_node *oldi_tx, int *companion_instance) @@ -430,6 +450,7 @@ void tidss_oldi_deinit(struct tidss_device *tidss) for (int i = 0; i < tidss->num_oldis; i++) { if (tidss->oldis[i]) { drm_bridge_remove(&tidss->oldis[i]->bridge); + tidss->is_ext_vp_clk[tidss->oldis[i]->parent_vp] = false; tidss->oldis[i] = NULL; } } @@ -580,6 +601,7 @@ int tidss_oldi_init(struct tidss_device *tidss) oldi->bridge.timings = &default_tidss_oldi_timings;
tidss->oldis[tidss->num_oldis++] = oldi; + tidss->is_ext_vp_clk[oldi->parent_vp] = true; oldi->tidss = tidss;
drm_bridge_add(&oldi->bridge);