On 26/07/19 9:48 PM, Shirley Her (SC) wrote:
> Fix data read/write error in HS200 mode due to chip DLL lock phase shift
More explanation is needed. See comment below where
sdhci_o2_error_recovery() is called.
>
> Signed-off-by:Shirley Her<shirley.her@xxxxxxxxxxxxxx>
> ---
> change in V2:
> 1. Use usleep_range instead of udelay
> 2. move dll_adjust_count to sdhci-pci-o2micro.c
>
> change in V1:
> 1. Add error recovery function to relock the DLL with correct phase
> 2. Retuning HS200 after DLL locked
> ---
> ---
> drivers/mmc/host/sdhci-pci-o2micro.c | 157 +++++++++++++++++++++++++++++------
> 1 file changed, 133 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c
> index 9dc4548..c43b2ce 100644
> --- a/drivers/mmc/host/sdhci-pci-o2micro.c
> +++ b/drivers/mmc/host/sdhci-pci-o2micro.c
> @@ -51,13 +51,60 @@
> #define O2_SD_VENDOR_SETTING2 0x1C8
> #define O2_SD_HW_TUNING_DISABLE BIT(4)
>
> -#define O2_PLL_WDT_CONTROL1 0x1CC
> +#define O2_PLL_DLL_WDT_CONTROL1 0x1CC
Renaming O2_PLL_WDT_CONTROL1 should be a separate patch.
> #define O2_PLL_FORCE_ACTIVE BIT(18)
> #define O2_PLL_LOCK_STATUS BIT(14)
> #define O2_PLL_SOFT_RESET BIT(12)
> +#define O2_DLL_LOCK_STATUS BIT(11)
>
> #define O2_SD_DETECT_SETTING 0x324
>
> +static const u32 dmdn_table[5] = {0x25100000, 0x2B1C0000,
> + 0x2C1A0000, 0x371B0000, 0x35100000};
> +static u8 dll_adjust_count;
This should be in a struct:
struct o2_host {
u8 dll_adjust_count;
}
> +static int sdhci_o2_get_cd(struct mmc_host *mmc);
Please make a separate patch that reorders the functions so that forward
declaration of sdhci_o2_get_cd() is not necessary.
> +
> +static void o2_pci_set_baseclk(struct sdhci_pci_chip *chip, u32 value)
> +{
> + u32 scratch_32;
> +
> + pci_read_config_dword(chip->pdev,
> + O2_SD_PLL_SETTING, &scratch_32);
> +
> + scratch_32 &= 0x0000FFFF;
> + scratch_32 |= value;
> +
> + pci_write_config_dword(chip->pdev,
> + O2_SD_PLL_SETTING, scratch_32);
> +}
> +
> +static int sdhci_o2_wait_dll_detect_lock(struct sdhci_host *host)
> +{
> + ktime_t timeout;
> + u32 scratch32;
> +
> + usleep_range(5000, 6000);
> + scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
> + if (!(scratch32 & O2_DLL_LOCK_STATUS)) {
> + pr_warn("%s: DLL is still unlocked after wait 5ms\n",
> + mmc_hostname(host->mmc));
> + }
> +
> + /* Detect 500 ms */
> + timeout = ktime_add_ms(ktime_get(), 500);
> + while (1) {
> + bool timedout = ktime_after(ktime_get(), timeout);
> +
> + scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
> + if (!(scratch32 & O2_DLL_LOCK_STATUS))
> + return 0;
> +
> + if (timedout)
> + return 1;
> + usleep_range(10, 1000);
> + }
> +}
> +
> static void sdhci_o2_set_tuning_mode(struct sdhci_host *host)
> {
> u16 reg;
> @@ -95,11 +142,85 @@ static void __sdhci_o2_execute_tuning(struct sdhci_host *host, u32 opcode)
> sdhci_reset_tuning(host);
> }
>
> +static int sdhci_o2_error_recovery(struct sdhci_pci_chip *chip,
> + struct sdhci_host *host)
> +{
> + int ret = 0;
> + u8 scratch_8 = 0;
> + u32 scratch_32 = 0;
Please add a blank line after local variable declaration
> + /* Disable clock */
> + sdhci_writeb(host, 0, SDHCI_CLOCK_CONTROL);
> +
> +DLL_ADJUST:
Please use a 'do', 'for' or 'while' loop.
> + if (dll_adjust_count >= 5) {
> + dll_adjust_count = 4;
> + pr_warn("%s: error recovery failed with the dll_adjust_count over max value.\n",
> + mmc_hostname(host->mmc));
Isn't it necessary to exit the loop here?
> + }
> +
> + /* UnLock WP */
> + ret = pci_read_config_byte(chip->pdev,
> + O2_SD_LOCK_WP, &scratch_8);
> + if (ret)
> + return ret;
> +
> + scratch_8 &= 0x7f;
> + pci_write_config_byte(chip->pdev, O2_SD_LOCK_WP, scratch_8);
> +
> + /* PLL software reset */
> + scratch_32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
> + scratch_32 |= O2_PLL_SOFT_RESET;
> + sdhci_writel(host, scratch_32, O2_PLL_DLL_WDT_CONTROL1);
> +
> + ret = pci_read_config_dword(chip->pdev,
> + O2_SD_FUNC_REG4,
> + &scratch_32);
> + /* Enable Base Clk setting change */
> + scratch_32 |= O2_SD_FREG4_ENABLE_CLK_SET;
> + pci_write_config_dword(chip->pdev, O2_SD_FUNC_REG4, scratch_32);
> + o2_pci_set_baseclk(chip, dmdn_table[dll_adjust_count]);
> +
> +
Please don't use multiple blank lines
> + /* Enable internal clock */
> + scratch_8 = SDHCI_CLOCK_INT_EN;
> + sdhci_writeb(host, scratch_8, SDHCI_CLOCK_CONTROL);
> +
> + if (sdhci_o2_get_cd(host->mmc)) {
> + if (sdhci_o2_wait_dll_detect_lock(host)) {
> + scratch_8 |= SDHCI_CLOCK_CARD_EN;
> + sdhci_writeb(host, scratch_8, SDHCI_CLOCK_CONTROL);
> + ret = 1;
> + } else {
> +
Blank lines aren't necessary after an open brace '{'
> + pr_warn("%s: DLL unlocked when dll_adjust_count is %d.\n",
> + mmc_hostname(host->mmc), dll_adjust_count);
> + dll_adjust_count++;
> + goto DLL_ADJUST;
> + }
> + } else
> + goto DLL_ADJUST;
braces {} should be used on all arms of this statement
> +
> + /* Lock WP */
> + ret = pci_read_config_byte(chip->pdev,
> + O2_SD_LOCK_WP, &scratch_8);
> + if (ret)
> + return ret;
> + scratch_8 |= 0x80;
> + pci_write_config_byte(chip->pdev, O2_SD_LOCK_WP, scratch_8);
> + return ret;
> +}
> +
> static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode)
> {
> struct sdhci_host *host = mmc_priv(mmc);
> + struct sdhci_pci_slot *slot = sdhci_priv(host);
This is how you get a reference to o2_host:
struct o2_host *o2_host = sdhci_pci_priv(slot);
> int current_bus_width = 0;
>
> +
Please don't use multiple blank lines
> + if (dll_adjust_count)
dll_adjust_count should be in struct o2_host
o2_host->dll_adjust_count
> + sdhci_o2_error_recovery(slot->chip, host);
Tuning will be executed whenever the system resumes, which is not an error.
Can you explain when error recovery is needed, and how this patch works.
> +
> + dll_adjust_count++;
> /*
> * This handler only implements the eMMC tuning that is specific to
> * this controller. Fall back to the standard method for other TIMING.
> @@ -131,23 +252,11 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode)
> mmc->ios.bus_width = MMC_BUS_WIDTH_8;
> sdhci_set_bus_width(host, current_bus_width);
> }
> -
Please avoid unrelated white space changes.
> host->flags &= ~SDHCI_HS400_TUNING;
> return 0;
> }
>
> -static void o2_pci_set_baseclk(struct sdhci_pci_chip *chip, u32 value)
> -{
> - u32 scratch_32;
> - pci_read_config_dword(chip->pdev,
> - O2_SD_PLL_SETTING, &scratch_32);
>
> - scratch_32 &= 0x0000FFFF;
> - scratch_32 |= value;
> -
> - pci_write_config_dword(chip->pdev,
> - O2_SD_PLL_SETTING, scratch_32);
> -}
>
> static void o2_pci_led_enable(struct sdhci_pci_chip *chip)
> {
> @@ -316,23 +425,23 @@ static void sdhci_o2_enable_internal_clock(struct sdhci_host *host)
> u32 scratch32;
>
> /* PLL software reset */
> - scratch32 = sdhci_readl(host, O2_PLL_WDT_CONTROL1);
> + scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
> scratch32 |= O2_PLL_SOFT_RESET;
> - sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
> + sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
> udelay(1);
> scratch32 &= ~(O2_PLL_SOFT_RESET);
> - sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
> + sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
>
> /* PLL force active */
> scratch32 |= O2_PLL_FORCE_ACTIVE;
> - sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
> + sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
>
> /* Wait max 20 ms */
> timeout = ktime_add_ms(ktime_get(), 20);
> while (1) {
> bool timedout = ktime_after(ktime_get(), timeout);
>
> - scratch = sdhci_readw(host, O2_PLL_WDT_CONTROL1);
> + scratch = sdhci_readw(host, O2_PLL_DLL_WDT_CONTROL1);
> if (scratch & O2_PLL_LOCK_STATUS)
> break;
> if (timedout) {
> @@ -350,16 +459,16 @@ static void sdhci_o2_enable_internal_clock(struct sdhci_host *host)
>
> out:
> /* Cancel PLL force active */
> - scratch32 = sdhci_readl(host, O2_PLL_WDT_CONTROL1);
> + scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
> scratch32 &= ~O2_PLL_FORCE_ACTIVE;
> - sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
> + sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
> }
>
> static int sdhci_o2_get_cd(struct mmc_host *mmc)
> {
> struct sdhci_host *host = mmc_priv(mmc);
> -
Please keep the blank line after declarations.
> - sdhci_o2_enable_internal_clock(host);
> + if (!(sdhci_readw(host, O2_PLL_DLL_WDT_CONTROL1) & O2_PLL_LOCK_STATUS))
> + sdhci_o2_enable_internal_clock(host);
>
> return !!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT);
> }
> @@ -369,7 +478,7 @@ static void sdhci_o2_enable_clk(struct sdhci_host *host, u16 clk)
> /* Enable internal clock */
> clk |= SDHCI_CLOCK_INT_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> -
> + sdhci_o2_enable_internal_clock(host);
> if (sdhci_o2_get_cd(host->mmc)) {
> clk |= SDHCI_CLOCK_CARD_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> @@ -400,7 +509,7 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
>
> chip = slot->chip;
> host = slot->host;
> -
> + dll_adjust_count = 0;
> caps = sdhci_readl(host, SDHCI_CAPABILITIES);
>
> /*
>
Set up o2_host like this:
diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c
b/drivers/mmc/host/sdhci-pci-o2micro.c
index c43b2cecdf30..cfe57f23dcf1 100644
--- a/drivers/mmc/host/sdhci-pci-o2micro.c
+++ b/drivers/mmc/host/sdhci-pci-o2micro.c
@@ -796,4 +796,5 @@ const struct sdhci_pci_fixes sdhci_o2 = {
.resume = sdhci_pci_o2_resume,
#endif
.ops = &sdhci_pci_o2_ops,
+ .priv_size = sizeof(struct o2_host),
};
