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Message-ID: <48c25923-432f-25df-caa8-30b38f4ac9f7@intel.com>
Date: Tue, 6 Aug 2019 14:54:29 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: "Chevron Li (WH)" <chevron.li@...hubtech.com>,
Ulf Hansson <ulf.hansson@...aro.org>,
"linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Cc: "Max Huang (SC)" <max.huang@...hubtech.com>,
"Xiaoguang Yu (WH)" <xiaoguang.yu@...hubtech.com>,
"Shirley Her (SC)" <shirley.her@...hubtech.com>,
"Shaper Liu (WH)" <shaper.liu@...hubtech.com>,
"Louis Lu (TP)" <louis.lu@...hubtech.com>
Subject: Re: [PATCH V2 1/1] mmc: sdhci: Fix O2 Host data read/write DLL lock
Phase shift issue
On 2/08/19 1:53 PM, Chevron Li (WH) wrote:
> Hi, Adrian,
>
> Firstly, really appreciate for your valuable suggestions.
>
> For your question that " 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."
>
> We have blow questions need your help.
>
> 1. In which cases card initialization module(mmc_init_card) will be called after first init completed exclude error happened? Whether the case is Resume from idle or sleep, any case else?
> In which cases tuning module(execute_tuning) will be called after first init completed exclude error happened? Whether the case is Resume from idle or sleep, any case else?
Re-tuning can happen after CRC-error, resume, or re-tuning timer timeout.
Also as part of re-initializing a card after repeated errors in
mmc_blk_mq_rw_recovery.
>
> Because in Bayhub driver, once tuning module is called exclude first initialization the tuning call will be thought as error recovery tuning.
>
> 2. If the tuning and initialization are called cases are not clearly, can we get the mmc_blk_request error status(block request error) in tuning module?
It would be better for the Bayhub driver to save error status.
>
> What method can be used to get the structure mmc_blk_request in tuning module(execute_tuning)
>
> 3. If there is no method to get the block request error status in tuning module, we want to add a variable to save the error status during block request,
> and use it in tuning module as the condition to call Bayhub dll recovery.
>
> So which structure the variable should be added, and how to acquire it in mmc_blk_mq_rw_recovery, how to acquire it in execute_tuning.
>
> Looking forward to your reply!
>
> Thanks,
> Chevron
>
>
> -----Original Message-----
> From: Adrian Hunter [mailto:adrian.hunter@...el.com]
> Sent: 2019年7月29日 20:13
> To: Shirley Her (SC); Ulf Hansson; linux-mmc@...r.kernel.org; linux-kernel@...r.kernel.org
> Cc: Louis Lu (TP); Max Huang (SC); Chevron Li (WH)
> Subject: Re: [PATCH V2 1/1] mmc: sdhci: Fix O2 Host data read/write DLL lock Phase shift issue
>
> 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@...hubtech.com>
>> ---
>> 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),
> };
>
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