[PATCH v2 0/2] phy: rockchip-emmc: fixes emmc-phy power on failed with rk3399 SoCs

[PATCH v2 0/2] phy: rockchip-emmc: fixes emmc-phy power on failed with rk3399 SoCs

[Caesar Wang]

Hi Kishon,

Since the Shawn isn't available, I take over this series patches for now.

As the original bug had tracked on https://issuetracker.google.com/71561742.
In some cases, the mmc phy power on failed during booting up.
The log as below:
...
[   2.375333] rockchip_emmc_phy_power: caldone timeout.
[    2.377815] phy phy-ff770000.syscon:phy at f780.4: phy poweron failed --> -110
...
[    2.489295] mmc0: mmc_select_hs400es failed, error -110
[    2.489302] mmc0: error -110 whilst initialising MMC card
..

The actual emulate, the wait 5us for calpad busy trimming, that's no enough.
We need give the enough margin for it.

Verified on url =
        https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4
This series patches can apply and bring up with kernel-next on rk3399 chromebook.

-Caesar


Changes in v2:
- print the return valut with regmap_read_poll_timeout failing.
- As Brian commented on https://patchwork.kernel.org/patch/10139891/,
  changed the note and added to print error value with
  regmap_read_poll_timeout API.

Shawn Lin (2):
  phy: rockchip-emmc: retry calpad busy trimming
  phy: rockchip-emmc: use regmap_read_poll_timeout to poll dllrdy

 drivers/phy/rockchip/phy-rockchip-emmc.c | 60 +++++++++++++++-----------------
 1 file changed, 28 insertions(+), 32 deletions(-)

-- 
2.7.4

[PATCH v2 1/2] phy: rockchip-emmc: retry calpad busy trimming

[Caesar Wang]

From: Shawn Lin <shawn.lin@rock-chips.com>

It turns out that 5us isn't enough for all cases, so let's
retry some more times to wait for caldone.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
---

Changes in v2:
- print the return valut with regmap_read_poll_timeout failing.

 drivers/phy/rockchip/phy-rockchip-emmc.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c
index f1b24f1..574838f 100644
--- a/drivers/phy/rockchip/phy-rockchip-emmc.c
+++ b/drivers/phy/rockchip/phy-rockchip-emmc.c
@@ -76,6 +76,10 @@
 #define PHYCTRL_OTAPDLYSEL_MASK		0xf
 #define PHYCTRL_OTAPDLYSEL_SHIFT	0x7
 
+#define PHYCTRL_IS_CALDONE(x) \
+	((((x) >> PHYCTRL_CALDONE_SHIFT) & \
+	  PHYCTRL_CALDONE_MASK) == PHYCTRL_CALDONE_DONE)
+
 struct rockchip_emmc_phy {
 	unsigned int	reg_offset;
 	struct regmap	*reg_base;
@@ -90,6 +94,7 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
 	unsigned int freqsel = PHYCTRL_FREQSEL_200M;
 	unsigned long rate;
 	unsigned long timeout;
+	int ret;
 
 	/*
 	 * Keep phyctrl_pdb and phyctrl_endll low to allow
@@ -160,17 +165,19 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
 				   PHYCTRL_PDB_SHIFT));
 
 	/*
-	 * According to the user manual, it asks driver to
-	 * wait 5us for calpad busy trimming
+	 * According to the user manual, it asks driver to wait 5us for
+	 * calpad busy trimming. However it is documented that this value is
+	 * PVT(A.K.A process,voltage and temperature) relevant, so some
+	 * failure cases are found which indicates we should be more tolerant
+	 * to calpad busy trimming.
 	 */
-	udelay(5);
-	regmap_read(rk_phy->reg_base,
-		    rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
-		    &caldone);
-	caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
-	if (caldone != PHYCTRL_CALDONE_DONE) {
-		pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
-		return -ETIMEDOUT;
+	ret = regmap_read_poll_timeout(rk_phy->reg_base,
+				       rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+				       caldone, PHYCTRL_IS_CALDONE(caldone),
+				       5, 50);
+	if (ret) {
+		pr_err("%s: caldone timeout, ret=%d\n", __func__, ret);
+		return ret;
 	}
 
 	/* Set the frequency of the DLL operation */
-- 
2.7.4

[PATCH v2 1/2] phy: rockchip-emmc: retry calpad busy trimming

[Doug Anderson]

Hi,

On Tue, Jan 9, 2018 at 11:37 PM, Caesar Wang <wxt@rock-chips.com> wrote:
> From: Shawn Lin <shawn.lin@rock-chips.com>
>
> It turns out that 5us isn't enough for all cases, so let's
> retry some more times to wait for caldone.
>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> Tested-by: Ziyuan Xu <xzy.xu@rock-chips.com>
> Signed-off-by: Caesar Wang <wxt@rock-chips.com>
> ---
>
> Changes in v2:
> - print the return valut with regmap_read_poll_timeout failing.

I agree with Brian that it was quite confusing to see a v2 from both
you and Shawn.


>  drivers/phy/rockchip/phy-rockchip-emmc.c | 27 +++++++++++++++++----------
>  1 file changed, 17 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c
> index f1b24f1..574838f 100644
> --- a/drivers/phy/rockchip/phy-rockchip-emmc.c
> +++ b/drivers/phy/rockchip/phy-rockchip-emmc.c
> @@ -76,6 +76,10 @@
>  #define PHYCTRL_OTAPDLYSEL_MASK                0xf
>  #define PHYCTRL_OTAPDLYSEL_SHIFT       0x7
>
> +#define PHYCTRL_IS_CALDONE(x) \
> +       ((((x) >> PHYCTRL_CALDONE_SHIFT) & \
> +         PHYCTRL_CALDONE_MASK) == PHYCTRL_CALDONE_DONE)
> +
>  struct rockchip_emmc_phy {
>         unsigned int    reg_offset;
>         struct regmap   *reg_base;
> @@ -90,6 +94,7 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
>         unsigned int freqsel = PHYCTRL_FREQSEL_200M;
>         unsigned long rate;
>         unsigned long timeout;
> +       int ret;
>
>         /*
>          * Keep phyctrl_pdb and phyctrl_endll low to allow
> @@ -160,17 +165,19 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
>                                    PHYCTRL_PDB_SHIFT));
>
>         /*
> -        * According to the user manual, it asks driver to
> -        * wait 5us for calpad busy trimming
> +        * According to the user manual, it asks driver to wait 5us for
> +        * calpad busy trimming. However it is documented that this value is
> +        * PVT(A.K.A process,voltage and temperature) relevant, so some
> +        * failure cases are found which indicates we should be more tolerant
> +        * to calpad busy trimming.
>          */
> -       udelay(5);
> -       regmap_read(rk_phy->reg_base,
> -                   rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
> -                   &caldone);
> -       caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
> -       if (caldone != PHYCTRL_CALDONE_DONE) {
> -               pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
> -               return -ETIMEDOUT;
> +       ret = regmap_read_poll_timeout(rk_phy->reg_base,
> +                                      rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
> +                                      caldone, PHYCTRL_IS_CALDONE(caldone),
> +                                      5, 50);
>
> +       if (ret) {
> +               pr_err("%s: caldone timeout, ret=%d\n", __func__, ret);

In Shawn's v2, AKA <https://patchwork.kernel.org/patch/10154795/>,
this says "caldone failed", which I like better since not all failures
will be timeouts.

[PATCH v2 2/2] phy: rockchip-emmc: use regmap_read_poll_timeout to poll dllrdy

[Caesar Wang]

From: Shawn Lin <shawn.lin@rock-chips.com>

Just use the API instead of open-coding it, no functional change
intended.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>

---

Changes in v2:
- As Brian commented on https://patchwork.kernel.org/patch/10139891/,
  changed the note and added to print error value with
  regmap_read_poll_timeout API.

 drivers/phy/rockchip/phy-rockchip-emmc.c | 33 +++++++++++---------------------
 1 file changed, 11 insertions(+), 22 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c
index 574838f..343c623 100644
--- a/drivers/phy/rockchip/phy-rockchip-emmc.c
+++ b/drivers/phy/rockchip/phy-rockchip-emmc.c
@@ -79,6 +79,9 @@
 #define PHYCTRL_IS_CALDONE(x) \
 	((((x) >> PHYCTRL_CALDONE_SHIFT) & \
 	  PHYCTRL_CALDONE_MASK) == PHYCTRL_CALDONE_DONE)
+#define PHYCTRL_IS_DLLRDY(x) \
+	((((x) >> PHYCTRL_DLLRDY_SHIFT) & \
+	  PHYCTRL_DLLRDY_MASK) == PHYCTRL_DLLRDY_DONE)
 
 struct rockchip_emmc_phy {
 	unsigned int	reg_offset;
@@ -93,7 +96,6 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
 	unsigned int dllrdy;
 	unsigned int freqsel = PHYCTRL_FREQSEL_200M;
 	unsigned long rate;
-	unsigned long timeout;
 	int ret;
 
 	/*
@@ -217,28 +219,15 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
 	 * NOTE: There appear to be corner cases where the DLL seems to take
 	 * extra long to lock for reasons that aren't understood.  In some
 	 * extreme cases we've seen it take up to over 10ms (!).  We'll be
-	 * generous and give it 50ms.  We still busy wait here because:
-	 * - In most cases it should be super fast.
-	 * - This is not called lots during normal operation so it shouldn't
-	 *   be a power or performance problem to busy wait.  We expect it
-	 *   only at boot / resume.  In both cases, eMMC is probably on the
-	 *   critical path so busy waiting a little extra time should be OK.
+	 * generous and give it 50ms.
 	 */
-	timeout = jiffies + msecs_to_jiffies(50);
-	do {
-		udelay(1);
-
-		regmap_read(rk_phy->reg_base,
-			rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
-			&dllrdy);
-		dllrdy = (dllrdy >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK;
-		if (dllrdy == PHYCTRL_DLLRDY_DONE)
-			break;
-	} while (!time_after(jiffies, timeout));
-
-	if (dllrdy != PHYCTRL_DLLRDY_DONE) {
-		pr_err("rockchip_emmc_phy_power: dllrdy timeout.\n");
-		return -ETIMEDOUT;
+	ret = regmap_read_poll_timeout(rk_phy->reg_base,
+				       rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+				       dllrdy, PHYCTRL_IS_DLLRDY(dllrdy),
+				       1, 50 * USEC_PER_MSEC);
+	if (ret) {
+		pr_err("%s: dllrdy timeout. ret=%d\n", __func__, ret);
+		return ret;
 	}
 
 	return 0;
-- 
2.7.4

[PATCH v2 2/2] phy: rockchip-emmc: use regmap_read_poll_timeout to poll dllrdy

[Doug Anderson]

Hi,

On Tue, Jan 9, 2018 at 11:37 PM, Caesar Wang <wxt@rock-chips.com> wrote:
> From: Shawn Lin <shawn.lin@rock-chips.com>
>
> Just use the API instead of open-coding it, no functional change
> intended.
>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> Reviewed-by: Brian Norris <briannorris@chromium.org>
> Signed-off-by: Caesar Wang <wxt@rock-chips.com>
>
> ---
>
> Changes in v2:
> - As Brian commented on https://patchwork.kernel.org/patch/10139891/,
>   changed the note and added to print error value with
>   regmap_read_poll_timeout API.
>
>  drivers/phy/rockchip/phy-rockchip-emmc.c | 33 +++++++++++---------------------
>  1 file changed, 11 insertions(+), 22 deletions(-)

See comments in Shawn's v2.  AKA: <https://patchwork.kernel.org/patch/10154797/>