From: Dmitry Baryshkov dmitry.baryshkov@linaro.org
[ Upstream commit 1e0a97f84d73ea1182740f62069690c7f3271abb ]
If the dispcc uses CLK_OPS_PARENT_ENABLE (e.g. on QCM2290), CCF can try enabling VCO before the rate has been programmed. This can cause clock lockups and/or other boot issues. Program the VCO to the minimal PLL rate if the read rate is 0 Hz.
Cc: Konrad Dybcio konrad.dybcio@linaro.org Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Reported-by: Vladimir Zapolskiy vladimir.zapolskiy@linaro.org Reported-by: Konrad Dybcio konrad.dybcio@linaro.org Reviewed-by: Konrad Dybcio konrad.dybcio@linaro.org Fixes: f079f6d999cb ("drm/msm/dsi: Add PHY/PLL for 8x96") Patchwork: https://patchwork.freedesktop.org/patch/534813/ Link: https://lore.kernel.org/r/20230501011257.3460103-1-dmitry.baryshkov@linaro.o... Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c index 9f488adea7f54..3ce45b023e637 100644 --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c @@ -539,6 +539,9 @@ static int dsi_pll_14nm_vco_prepare(struct clk_hw *hw) if (unlikely(pll_14nm->phy->pll_on)) return 0;
+ if (dsi_pll_14nm_vco_recalc_rate(hw, VCO_REF_CLK_RATE) == 0) + dsi_pll_14nm_vco_set_rate(hw, pll_14nm->phy->cfg->min_pll_rate, VCO_REF_CLK_RATE); + dsi_phy_write(base + REG_DSI_14nm_PHY_PLL_VREF_CFG1, 0x10); dsi_phy_write(cmn_base + REG_DSI_14nm_PHY_CMN_PLL_CNTRL, 1);