From: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx> commit 90b7c1c66132c20e8a550006011a3cbfb73dbfc1 upstream. The downstream driver models this PLL lock check as an if-elseif-else. The only way to reach the else case where pll_locked=true [1] is by succeeding both readl_poll_timeout_atomic calls (which return zero on success) in the if _and_ elseif condition. Hence both the "lock" and "ready" bit need to be tested in the SM_READY_STATUS register before considering the PLL locked and ready to go. Tested on the Sony Xperia XA2 Ultra (nile-discovery, sdm630). [1]: https://source.codeaurora.org/quic/la/kernel/msm-4.19/tree/drivers/clk/qcom/mdss/mdss-dsi-pll-14nm-util.c?h=LA.UM.9.2.1.r1-08000-sdm660.0#n302 Fixes: f079f6d999cb ("drm/msm/dsi: Add PHY/PLL for 8x96") Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210906202552.824598-1-marijn.suijten@xxxxxxxxxxxxxx Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c | 30 ++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c @@ -110,14 +110,13 @@ static struct dsi_pll_14nm *pll_14nm_lis static bool pll_14nm_poll_for_ready(struct dsi_pll_14nm *pll_14nm, u32 nb_tries, u32 timeout_us) { - bool pll_locked = false; + bool pll_locked = false, pll_ready = false; void __iomem *base = pll_14nm->phy->pll_base; u32 tries, val; tries = nb_tries; while (tries--) { - val = dsi_phy_read(base + - REG_DSI_14nm_PHY_PLL_RESET_SM_READY_STATUS); + val = dsi_phy_read(base + REG_DSI_14nm_PHY_PLL_RESET_SM_READY_STATUS); pll_locked = !!(val & BIT(5)); if (pll_locked) @@ -126,23 +125,24 @@ static bool pll_14nm_poll_for_ready(stru udelay(timeout_us); } - if (!pll_locked) { - tries = nb_tries; - while (tries--) { - val = dsi_phy_read(base + - REG_DSI_14nm_PHY_PLL_RESET_SM_READY_STATUS); - pll_locked = !!(val & BIT(0)); + if (!pll_locked) + goto out; - if (pll_locked) - break; + tries = nb_tries; + while (tries--) { + val = dsi_phy_read(base + REG_DSI_14nm_PHY_PLL_RESET_SM_READY_STATUS); + pll_ready = !!(val & BIT(0)); - udelay(timeout_us); - } + if (pll_ready) + break; + + udelay(timeout_us); } - DBG("DSI PLL is %slocked", pll_locked ? "" : "*not* "); +out: + DBG("DSI PLL is %slocked, %sready", pll_locked ? "" : "*not* ", pll_ready ? "" : "*not* "); - return pll_locked; + return pll_locked && pll_ready; } static void dsi_pll_14nm_config_init(struct dsi_pll_config *pconf)