From: Krzysztof Kozlowski Date: Tue, 10 Jun 2025 14:05:47 +0000 (+0200) Subject: drm/msm/dsi/phy_7nm: Fix missing initial VCO rate X-Git-Tag: v6.18-rc1~134^2~10^2~52 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5ddcb0cb9d10e6e70a68e0cb8f0b8e3a7eb8ccaf;p=thirdparty%2Flinux.git drm/msm/dsi/phy_7nm: Fix missing initial VCO rate Driver unconditionally saves current state on first init in dsi_pll_7nm_init(), but does not save the VCO rate, only some of the divider registers. The state is then restored during probe/enable via msm_dsi_phy_enable() -> msm_dsi_phy_pll_restore_state() -> dsi_7nm_pll_restore_state(). Restoring calls dsi_pll_7nm_vco_set_rate() with pll_7nm->vco_current_rate=0, which basically overwrites existing rate of VCO and messes with clock hierarchy, by setting frequency to 0 to clock tree. This makes anyway little sense - VCO rate was not saved, so should not be restored. If PLL was not configured configure it to minimum rate to avoid glitches and configuring entire in clock hierarchy to 0 Hz. Reviewed-by: Dmitry Baryshkov Signed-off-by: Krzysztof Kozlowski Patchwork: https://patchwork.freedesktop.org/patch/657827/ Link: https://lore.kernel.org/r/20250610-b4-sm8750-display-v6-9-ee633e3ddbff@linaro.org Signed-off-by: Dmitry Baryshkov --- diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c index eb912aa3937d0..2c2bbda46c78e 100644 --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c @@ -846,6 +846,12 @@ static int dsi_pll_7nm_init(struct msm_dsi_phy *phy) /* TODO: Remove this when we have proper display handover support */ msm_dsi_phy_pll_save_state(phy); + /* + * Store also proper vco_current_rate, because its value will be used in + * dsi_7nm_pll_restore_state(). + */ + if (!dsi_pll_7nm_vco_recalc_rate(&pll_7nm->clk_hw, VCO_REF_CLK_RATE)) + pll_7nm->vco_current_rate = pll_7nm->phy->cfg->min_pll_rate; return 0; }