Am Dienstag, 28. September 2021, 23:35:50 CEST schrieb Brian Norris:
> Since commit 43c2de1002d2, we perform most HW configuration in the
> bind() function. This configuration may be lost on suspend/resume, so we
> need to call it again. That may lead to errors like this after system
> suspend/resume:
>
> dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
> panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110
>
> Tested on Acer Chromebook Tab 10 (RK3399 Gru-Scarlet).
>
> Note that early mailing list versions of this driver borrowed Rockchip's
> downstream/BSP solution, to do HW configuration in mode_set() (which
> *is* called at the appropriate pre-enable() times),
not always though. In non-atomic settings .mode_set actually doesn't
seem to be called every time. I've experienced this when drm disables
atomic when X11 is running.
So having real suspend/resume callbacks makes quite a lot of sense :-)
Heiko
> but that was
> discarded along the way. I've avoided that still, because mode_set()
> documentation doesn't suggest this kind of purpose as far as I can tell.
>
> Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
> ---
>
> Changes in v3:
> - New patch, to fix related PM issue discovered after patch 1
>
> .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c | 37 +++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> index 45676b23c019..21c67343cc6c 100644
> --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> @@ -268,6 +268,8 @@ struct dw_mipi_dsi_rockchip {
> struct dw_mipi_dsi *dmd;
> const struct rockchip_dw_dsi_chip_data *cdata;
> struct dw_mipi_dsi_plat_data pdata;
> +
> + bool dsi_bound;
> };
>
> struct dphy_pll_parameter_map {
> @@ -964,6 +966,8 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev,
> goto out_pm_runtime;
> }
>
> + dsi->dsi_bound = true;
> +
> return 0;
>
> out_pm_runtime:
> @@ -983,6 +987,8 @@ static void dw_mipi_dsi_rockchip_unbind(struct device *dev,
> if (dsi->is_slave)
> return;
>
> + dsi->dsi_bound = false;
> +
> dw_mipi_dsi_unbind(dsi->dmd);
>
> clk_disable_unprepare(dsi->pllref_clk);
> @@ -1277,6 +1283,36 @@ static const struct phy_ops dw_mipi_dsi_dphy_ops = {
> .exit = dw_mipi_dsi_dphy_exit,
> };
>
> +static int __maybe_unused dw_mipi_dsi_rockchip_resume(struct device *dev)
> +{
> + struct dw_mipi_dsi_rockchip *dsi = dev_get_drvdata(dev);
> + int ret;
> +
> + /*
> + * Re-configure DSI state, if we were previously initialized. We need
> + * to do this before rockchip_drm_drv tries to re-enable() any panels.
> + */
> + if (dsi->dsi_bound) {
> + ret = clk_prepare_enable(dsi->grf_clk);
> + if (ret) {
> + DRM_DEV_ERROR(dsi->dev, "Failed to enable grf_clk: %d\n", ret);
> + return ret;
> + }
> +
> + dw_mipi_dsi_rockchip_config(dsi);
> + if (dsi->slave)
> + dw_mipi_dsi_rockchip_config(dsi->slave);
> +
> + clk_disable_unprepare(dsi->grf_clk);
> + }
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops dw_mipi_dsi_rockchip_pm_ops = {
> + SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, dw_mipi_dsi_rockchip_resume)
> +};
> +
> static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -1594,6 +1630,7 @@ struct platform_driver dw_mipi_dsi_rockchip_driver = {
> .remove = dw_mipi_dsi_rockchip_remove,
> .driver = {
> .of_match_table = dw_mipi_dsi_rockchip_dt_ids,
> + .pm = &dw_mipi_dsi_rockchip_pm_ops,
> .name = "dw-mipi-dsi-rockchip",
> },
> };
>
