From: Marijn Suijten <marijn.suijten@somainline.org>
To: phone-devel@vger.kernel.org
Cc: ~postmarketos/upstreaming@lists.sr.ht,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@somainline.org>,
Konrad Dybcio <konrad.dybcio@somainline.org>,
Martin Botka <martin.botka@somainline.org>,
Jami Kettunen <jami.kettunen@somainline.org>,
Pavel Dubrova <pashadubrova@gmail.com>,
Marijn Suijten <marijn.suijten@somainline.org>,
Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
Abhinav Kumar <abhinavk@codeaurora.org>,
Archit Taneja <architt@codeaurora.org>,
linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH] drm/msm/dsi: dsi_phy_14nm: Take ready-bit into account in poll_for_ready
Date: Mon, 6 Sep 2021 22:25:51 +0200 [thread overview]
Message-ID: <20210906202552.824598-1-marijn.suijten@somainline.org> (raw)
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@somainline.org>
---
drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c | 30 +++++++++++-----------
1 file changed, 15 insertions(+), 15 deletions(-)
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 8905f365c932..789b08c24d25 100644
--- 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_list[DSI_MAX];
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(struct dsi_pll_14nm *pll_14nm,
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)
--
2.33.0
next reply other threads:[~2021-09-06 20:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-06 20:25 Marijn Suijten [this message]
2021-09-06 20:25 ` [PATCH] drm/msm/dsi: dsi_phy_14nm: Take ready-bit into account in poll_for_ready Marijn Suijten
2021-10-01 17:01 ` Dmitry Baryshkov
2021-10-01 17:01 ` Dmitry Baryshkov
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