Commit 2ec56b23 authored Jan 24, 2023 by Dmitry Baryshkov

drm/msm/dsi: properly handle the case of empty OPP table in dsi_mgr_bridge_mode_valid

It was left unnoticed during the review that even if there is no OPP
table in device tree, one will be created by a call to the function
devm_pm_opp_set_clkname(). This leads to dsi_mgr_bridge_mode_valid()
rejecting all modes if DT contains no OPP table for the DSI host.

Rework dsi_mgr_bridge_mode_valid() to handle this case by actually
checking that the table is populated with frequency entries before
returning an error.

Fixes: 8328041b ("drm/msm/dsi: implement opp table based check for dsi_mgr_bridge_mode_valid()")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/520076/
Link: https://lore.kernel.org/r/20230124203600.3488766-1-dmitry.baryshkov@linaro.org

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

parent a7efe60e

drivers/gpu/drm/msm/dsi/dsi_manager.c

+10 −9

Original line number	Diff line number	Diff line
		@@ -456,18 +456,19 @@ static enum drm_mode_status dsi_mgr_bridge_mode_valid(struct drm_bridge *bridge,

		byte_clk_rate = dsi_byte_clk_get_rate(host, IS_BONDED_DSI(), mode);

		opp = dev_pm_opp_find_freq_ceil(&pdev->dev, &byte_clk_rate);
		if (!IS_ERR(opp)) {
		dev_pm_opp_put(opp);
		} else if (PTR_ERR(opp) == -ERANGE) {
		/*
		* fail all errors except -ENODEV as that could mean that opp
		* table is not yet implemented
		* An empty table is created by devm_pm_opp_set_clkname() even
		* if there is none. Thus find_freq_ceil will still return
		* -ERANGE in such case.
		*/
		opp = dev_pm_opp_find_freq_ceil(&pdev->dev, &byte_clk_rate);
		if (IS_ERR(opp)) {
		if (PTR_ERR(opp) == -ERANGE)
		if (dev_pm_opp_get_opp_count(&pdev->dev) != 0)
		return MODE_CLOCK_RANGE;
		else if (PTR_ERR(opp) != -ENODEV)
		return MODE_ERROR;
		} else {
		dev_pm_opp_put(opp);
		return MODE_ERROR;
		}

		return msm_dsi_host_check_dsc(host, mode);