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@vger.kernel.org Signed-off-by: Brian Norris briannorris@chromium.org

---

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", },

};