Hi Ondřej, On Sat, Jun 17, 2023 at 05:06:33PM +0200, Ondřej Jirman wrote: > From: Ondrej Jirman <megi@xxxxxx> > > Before this patch, booting to Linux VT and doing a simple: > > echo 2 > /sys/class/graphics/fb0/blank > echo 0 > /sys/class/graphics/fb0/blank > > would result in failures to re-enable the panel. Mode set callback is > called only once during boot in this scenario, while calls to > enable/disable callbacks are balanced afterwards. The driver doesn't > work unless userspace calls modeset before enabling the CRTC/connector. > > This patch moves enabling of the DSI host from mode_set into pre_enable > callback, and removes some old hacks where this bridge driver is > directly calling into other bridge driver's callbacks. > > pre_enable_prev_first flag is set on the panel's bridge so that panel > drivers will get their prepare function called between DSI host's > pre_enable and enable callbacks, so that they get a chance to > perform panel setup while DSI host is already enabled in command > mode. Otherwise panel's prepare would be called before DSI host > is enabled, and any DSI communication used in prepare callback > would fail. > > With all these changes, the enable/disable sequence is now well > balanced, and host's and panel's callbacks are called in proper order > documented in the drm_panel API documentation without needing the old > hacks. (Mainly that panel->prepare is called when DSI host is ready to > allow the panel driver to send DSI commands and vice versa during > disable.) > > Tested on Pinephone Pro. Trace of the callbacks follows. > > Before: > > [ 1.253882] dw-mipi-dsi-rockchip ff960000.dsi: mode_set > [ 1.290732] panel-himax-hx8394 ff960000.dsi.0: prepare > [ 1.475576] dw-mipi-dsi-rockchip ff960000.dsi: enable > [ 1.475593] panel-himax-hx8394 ff960000.dsi.0: enable > > echo 2 > /sys/class/graphics/fb0/blank > > [ 13.722799] panel-himax-hx8394 ff960000.dsi.0: disable > [ 13.774502] dw-mipi-dsi-rockchip ff960000.dsi: post_disable > [ 13.774526] panel-himax-hx8394 ff960000.dsi.0: unprepare > > echo 0 > /sys/class/graphics/fb0/blank > > [ 17.735796] panel-himax-hx8394 ff960000.dsi.0: prepare > [ 17.923522] dw-mipi-dsi-rockchip ff960000.dsi: enable > [ 17.923540] panel-himax-hx8394 ff960000.dsi.0: enable > [ 17.944330] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO > [ 17.944335] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 failed: -110 > [ 17.944340] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence failed: -110 > > echo 2 > /sys/class/graphics/fb0/blank > > [ 431.148583] panel-himax-hx8394 ff960000.dsi.0: disable > [ 431.169259] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO > [ 431.169268] panel-himax-hx8394 ff960000.dsi.0: Failed to enter sleep mode: -110 > [ 431.169282] dw-mipi-dsi-rockchip ff960000.dsi: post_disable > [ 431.169316] panel-himax-hx8394 ff960000.dsi.0: unprepare > [ 431.169357] pclk_mipi_dsi0 already disabled > > echo 0 > /sys/class/graphics/fb0/blank > > [ 432.796851] panel-himax-hx8394 ff960000.dsi.0: prepare > [ 432.981537] dw-mipi-dsi-rockchip ff960000.dsi: enable > [ 432.981568] panel-himax-hx8394 ff960000.dsi.0: enable > [ 433.002290] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO > [ 433.002299] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 failed: -110 > [ 433.002312] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence failed: -110 > > ----------------------------------------------------------------------- > > After: > > [ 1.248372] dw-mipi-dsi-rockchip ff960000.dsi: mode_set > [ 1.248704] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable > [ 1.285377] panel-himax-hx8394 ff960000.dsi.0: prepare > [ 1.468392] dw-mipi-dsi-rockchip ff960000.dsi: enable > [ 1.468421] panel-himax-hx8394 ff960000.dsi.0: enable > > echo 2 > /sys/class/graphics/fb0/blank > > [ 16.210357] panel-himax-hx8394 ff960000.dsi.0: disable > [ 16.261315] dw-mipi-dsi-rockchip ff960000.dsi: post_disable > [ 16.261339] panel-himax-hx8394 ff960000.dsi.0: unprepare > > echo 0 > /sys/class/graphics/fb0/blank > > [ 19.161453] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable > [ 19.197869] panel-himax-hx8394 ff960000.dsi.0: prepare > [ 19.382141] dw-mipi-dsi-rockchip ff960000.dsi: enable > [ 19.382158] panel-himax-hx8394 ff960000.dsi.0: enable > > Signed-off-by: Ondrej Jirman <megi@xxxxxx> Nice cleanup and fix. Have you consider if this need a Fixes: ? > --- > drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 28 +++++++++++-------- > 1 file changed, 16 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > index b2efecf7d160..352c6829259a 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > @@ -265,6 +265,7 @@ struct dw_mipi_dsi { > struct dw_mipi_dsi *master; /* dual-dsi master ptr */ > struct dw_mipi_dsi *slave; /* dual-dsi slave ptr */ > > + struct drm_display_mode mode; > const struct dw_mipi_dsi_plat_data *plat_data; > }; > > @@ -332,6 +333,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host, > if (IS_ERR(bridge)) > return PTR_ERR(bridge); > > + bridge->pre_enable_prev_first = true; > dsi->panel_bridge = bridge; > > drm_bridge_add(&dsi->bridge); > @@ -859,15 +861,6 @@ static void dw_mipi_dsi_bridge_post_atomic_disable(struct drm_bridge *bridge, > */ > dw_mipi_dsi_set_mode(dsi, 0); > > - /* > - * TODO Only way found to call panel-bridge post_disable & > - * panel unprepare before the dsi "final" disable... > - * This needs to be fixed in the drm_bridge framework and the API > - * needs to be updated to manage our own call chains... > - */ > - if (dsi->panel_bridge->funcs->post_disable) > - dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge); > - > if (phy_ops->power_off) > phy_ops->power_off(dsi->plat_data->priv_data); > > @@ -942,15 +935,25 @@ static void dw_mipi_dsi_mode_set(struct dw_mipi_dsi *dsi, > phy_ops->power_on(dsi->plat_data->priv_data); > } > > +static void dw_mipi_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge, > + struct drm_bridge_state *old_bridge_state) > +{ > + struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge); > + > + /* Power up the dsi ctl into a command mode */ > + dw_mipi_dsi_mode_set(dsi, &dsi->mode); > + if (dsi->slave) > + dw_mipi_dsi_mode_set(dsi->slave, &dsi->mode); > +} > + > static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge, > const struct drm_display_mode *mode, > const struct drm_display_mode *adjusted_mode) > { > struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge); > > - dw_mipi_dsi_mode_set(dsi, adjusted_mode); > - if (dsi->slave) > - dw_mipi_dsi_mode_set(dsi->slave, adjusted_mode); > + /* Store the display mode for later use in pre_enable callback */ > + memcpy(&dsi->mode, adjusted_mode, sizeof(dsi->mode)); > } Use drm_mode_copy here. With this fixed: Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>