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

[Caesar Wang]

Hi Kishon & Shawn,

As the 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@f780.4: phy poweron failed 
--> -110
...
[    2.489295] mmc0: mmc_select_hs400es failed, error -110
[    2.489302] mmc0: error -110 whilst initialising MMC card
..


在 2018年01月02日 10:21, Shawn Lin 写道:
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....@rock-chips.com>

Tested-by: Caesar Wang <w...@rock-chips.com>

I had tested on rk3399 chromebook, so feel free to add my tag.

-Caesar
---

  drivers/phy/rockchip/phy-rockchip-emmc.c | 21 +++++++++++++--------
  1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c 
b/drivers/phy/rockchip/phy-rockchip-emmc.c
index f1b24f1..512a6ef 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;
@@ -160,15 +164,16 @@ 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) {
+       if (regmap_read_poll_timeout(rk_phy->reg_base,
+                                    rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+                                    caldone, PHYCTRL_IS_CALDONE(caldone),
+                                    5, 50)) {
                pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
                return -ETIMEDOUT;
        }