In commit 43c2de1002d2, we moved most HW configuration to bind(), but we didn't move the runtime PM management. Therefore, depending on initial boot state, runtime-PM workqueue delays, and other timing factors, we may disable our power domain in between the hardware configuration (bind()) and when we enable the display. This can cause us to lose hardware state and fail to configure our display. For example:

dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO panel-innolux-p079zca ff960000.mipi.0: failed to write command 0

or:

dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110

We should match the runtime PM to the lifetime of the bind()/unbind() cycle.

Tested on Acer Chrometab 10 (RK3399 Gru-Scarlet), with panel drivers built either as modules or built-in.

Side notes: it seems one is more likely to see this problem when the panel driver is built into the kernel. I've also seen this problem bisect down to commits that simply changed Kconfig dependencies, because it changed the order in which driver init functions were compiled into the kernel, and therefore the ordering and timing of built-in device probe.

Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()") Link: https://lore.kernel.org/linux-rockchip/9aedfb528600ecf871885f7293ca4207c84d1... Reported-by: aleksandr.o.makarov@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Brian Norris briannorris@chromium.org Tested-by: Nícolas F. R. A. Prado nfraprado@collabora.com ---

(no changes since v2)

Changes in v2: - Clean up pm-runtime state in error cases. - Correct git hash for Fixes.

.../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c | 37 ++++++++++--------- 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c index a2262bee5aa4..45676b23c019 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c @@ -773,10 +773,6 @@ static void dw_mipi_dsi_encoder_enable(struct drm_encoder *encoder) if (mux < 0) return;

- pm_runtime_get_sync(dsi->dev); - if (dsi->slave) - pm_runtime_get_sync(dsi->slave->dev); - /* * For the RK3399, the clk of grf must be enabled before writing grf * register. And for RK3288 or other soc, this grf_clk must be NULL, @@ -795,20 +791,10 @@ static void dw_mipi_dsi_encoder_enable(struct drm_encoder *encoder) clk_disable_unprepare(dsi->grf_clk); }

-static void dw_mipi_dsi_encoder_disable(struct drm_encoder *encoder) -{ - struct dw_mipi_dsi_rockchip *dsi = to_dsi(encoder); - - if (dsi->slave) - pm_runtime_put(dsi->slave->dev); - pm_runtime_put(dsi->dev); -} - static const struct drm_encoder_helper_funcs dw_mipi_dsi_encoder_helper_funcs = { .atomic_check = dw_mipi_dsi_encoder_atomic_check, .enable = dw_mipi_dsi_encoder_enable, - .disable = dw_mipi_dsi_encoder_disable, };

static int rockchip_dsi_drm_create_encoder(struct dw_mipi_dsi_rockchip *dsi, @@ -938,10 +924,14 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev, put_device(second); }

+ pm_runtime_get_sync(dsi->dev); + if (dsi->slave) + pm_runtime_get_sync(dsi->slave->dev); + ret = clk_prepare_enable(dsi->pllref_clk); if (ret) { DRM_DEV_ERROR(dev, "Failed to enable pllref_clk: %d\n", ret); - return ret; + goto out_pm_runtime; }

/* @@ -953,7 +943,7 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev, ret = clk_prepare_enable(dsi->grf_clk); if (ret) { DRM_DEV_ERROR(dsi->dev, "Failed to enable grf_clk: %d\n", ret); - return ret; + goto out_pm_runtime; }

dw_mipi_dsi_rockchip_config(dsi); @@ -965,16 +955,23 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev, ret = rockchip_dsi_drm_create_encoder(dsi, drm_dev); if (ret) { DRM_DEV_ERROR(dev, "Failed to create drm encoder\n"); - return ret; + goto out_pm_runtime; }

ret = dw_mipi_dsi_bind(dsi->dmd, &dsi->encoder); if (ret) { DRM_DEV_ERROR(dev, "Failed to bind: %d\n", ret); - return ret; + goto out_pm_runtime; }

return 0; + +out_pm_runtime: + pm_runtime_put(dsi->dev); + if (dsi->slave) + pm_runtime_put(dsi->slave->dev); + + return ret; }

static void dw_mipi_dsi_rockchip_unbind(struct device *dev, @@ -989,6 +986,10 @@ static void dw_mipi_dsi_rockchip_unbind(struct device *dev, dw_mipi_dsi_unbind(dsi->dmd);

clk_disable_unprepare(dsi->pllref_clk); + + pm_runtime_put(dsi->dev); + if (dsi->slave) + pm_runtime_put(dsi->slave->dev); }

static const struct component_ops dw_mipi_dsi_rockchip_ops = {