Hi Michael On Thu, 9 Dec 2021 at 16:58, Michael Nazzareno Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx> wrote: > > Hi all > > On Sat, Oct 16, 2021 at 4:58 PM Michael Trimarchi > <michael@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > All the panel driver check the fact that their prepare/unprepare > > call was already called. It's not an ideal solution but fix > > for now the problem on ili9881c > > > > [ 9862.283296] ------------[ cut here ]------------ > > [ 9862.288490] unbalanced disables for vcc3v3_lcd > > [ 9862.293555] WARNING: CPU: 0 PID: 1 at drivers/regulator/core.c:2851 > > _regulator_disable+0xd4/0x190 > > > > from: > > > > [ 9862.038619] drm_panel_unprepare+0x2c/0x4c > > [ 9862.043212] panel_bridge_post_disable+0x18/0x24 > > [ 9862.048390] dw_mipi_dsi_bridge_post_disable+0x3c/0xf0 > > [ 9862.054153] drm_atomic_bridge_chain_post_disable+0x8c/0xd0 > > > > and: > > > > [ 9862.183103] drm_panel_unprepare+0x2c/0x4c > > [ 9862.187695] panel_bridge_post_disable+0x18/0x24 > > [ 9862.192872] drm_atomic_bridge_chain_post_disable+0x8c/0xd0 > > [ 9862.199117] disable_outputs+0x120/0x31c This is down to the dw-mipi-dsi driver calling the post_disable hook explicitly at [1], but then also allowing the framework to call it. The explicit call is down to limitations in the DSI support, so we can't control the DSI host state to a fine enough degree (an ongoing discussion [2] [3]). There shouldn't be a need to handle mismatched calling in individual panel drivers. Dave [1] https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c#L894 [2] https://lists.freedesktop.org/archives/dri-devel/2021-November/332060.html [3] https://lists.freedesktop.org/archives/dri-devel/2021-December/334007.html > > Signed-off-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx> > > --- > > drivers/gpu/drm/panel/panel-ilitek-ili9881c.c | 14 ++++++++++++++ > > 1 file changed, 14 insertions(+) > > > > diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c > > index 103a16018975..f75eecb0e65c 100644 > > --- a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c > > +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c > > @@ -52,6 +52,8 @@ struct ili9881c { > > > > struct regulator *power; > > struct gpio_desc *reset; > > + > > + bool prepared; > > }; > > > > I found that this can be a general problem. Should not mandatory to > track panel status > > DRM_PANEL_PREPARED > DRM_PANEL_ENABLED > > Michael > > #define ILI9881C_SWITCH_PAGE_INSTR(_page) \ > > @@ -707,6 +709,10 @@ static int ili9881c_prepare(struct drm_panel *panel) > > unsigned int i; > > int ret; > > > > + /* Preparing when already prepared is a no-op */ > > + if (ctx->prepared) > > + return 0; > > + > > /* Power the panel */ > > ret = regulator_enable(ctx->power); > > if (ret) > > @@ -745,6 +751,8 @@ static int ili9881c_prepare(struct drm_panel *panel) > > if (ret) > > return ret; > > > > + ctx->prepared = true; > > + > > return 0; > > } > > > > @@ -770,10 +778,16 @@ static int ili9881c_unprepare(struct drm_panel *panel) > > { > > struct ili9881c *ctx = panel_to_ili9881c(panel); > > > > + /* Unpreparing when already unprepared is a no-op */ > > + if (!ctx->prepared) > > + return 0; > > + > > mipi_dsi_dcs_enter_sleep_mode(ctx->dsi); > > regulator_disable(ctx->power); > > gpiod_set_value(ctx->reset, 1); > > > > + ctx->prepared = false; > > + > > return 0; > > } > > > > -- > > 2.25.1 > > > > > -- > Michael Nazzareno Trimarchi > Co-Founder & Chief Executive Officer > M. +39 347 913 2170 > michael@xxxxxxxxxxxxxxxxxxxx > __________________________________ > > Amarula Solutions BV > Joop Geesinkweg 125, 1114 AB, Amsterdam, NL > T. +31 (0)85 111 9172 > info@xxxxxxxxxxxxxxxxxxxx > www.amarulasolutions.com
