From: addy.ke@rock-chips•com (Addy)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 1/2] mmc: dw_mmc: fix bug that cause 'Timeout sending command'
Date: Wed, 11 Feb 2015 11:07:14 +0800 [thread overview]
Message-ID: <54DAC762.2050404@rock-chips.com> (raw)
In-Reply-To: <54D88560.4050808@samsung.com>
On 2015/02/09 18:01, Jaehoon Chung wrote:
> Hi, Addy.
>
> On 02/09/2015 04:25 PM, Addy Ke wrote:
>> Because of some uncertain factors, such as worse card or worse hardware,
>> DAT[3:0](the data lines) may be pulled down by card, and mmc controller
>> will be in busy state. This should not happend when mmc controller
>> send command to update card clocks. If this happends, mci_send_cmd will
>> be failed and we will get 'Timeout sending command', and then system will
>> be blocked. To avoid this, we need reset mmc controller.
>>
>> Signed-off-by: Addy Ke <addy.ke@rock-chips•com>
>> ---
>> drivers/mmc/host/dw_mmc.c | 28 ++++++++++++++++++++++++++++
>> 1 file changed, 28 insertions(+)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 4d2e3c2..b0b57e3 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -100,6 +100,7 @@ struct idmac_desc {
>> };
>> #endif /* CONFIG_MMC_DW_IDMAC */
>>
>> +static int dw_mci_card_busy(struct mmc_host *mmc);
>> static bool dw_mci_reset(struct dw_mci *host);
>> static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset);
>>
>> @@ -888,6 +889,31 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>> cmd, arg, cmd_status);
>> }
>>
>> +static void dw_mci_wait_busy(struct dw_mci_slot *slot)
>> +{
>> + struct dw_mci *host = slot->host;
>> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
>> +
>> + do {
>> + if (!dw_mci_card_busy(slot->mmc))
>> + return;
>> + cpu_relax();
>> + } while (time_before(jiffies, timeout));
>> +
>> + dev_err(host->dev, "Data busy (status %#x)\n",
>> + mci_readl(slot->host, STATUS));
>> +
>> + /*
>> + * Data busy, this should not happend when mmc controller send command
>> + * to update card clocks in non-volt-switch state. If it happends, we
>> + * should reset controller to avoid getting "Timeout sending command".
>> + */
>> + dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS);
> If reset is failed, then dw_mci_ctrl_reset should return "false".
>
> ret = dw_mci_ctrl_reset();
>
> WARN_ON(!ret || dw_mci_card_busy(slot->mmc));
>
> Is it right?
you are right, and I will update it in my next version patch. thank you.
>
> In my experiment, if reset is failed or card is busy, eMMC can't work anymore..right?
> I think this patch is reasonable to prevent blocking issue.
>
> Best Regards,
> Jaehoon Chung
>
>
>> +
>> + /* Fail to reset controller or still data busy, WARN_ON! */
>> + WARN_ON(dw_mci_card_busy(slot->mmc));
>> +}
>> +
>> static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
>> {
>> struct dw_mci *host = slot->host;
>> @@ -899,6 +925,8 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
>> /* We must continue to set bit 28 in CMD until the change is complete */
>> if (host->state == STATE_WAITING_CMD11_DONE)
>> sdmmc_cmd_bits |= SDMMC_CMD_VOLT_SWITCH;
>> + else
>> + dw_mci_wait_busy(slot);
>>
>> if (!clock) {
>> mci_writel(host, CLKENA, 0);
>>
>
>
>
next prev parent reply other threads:[~2015-02-11 3:07 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-05 11:13 [PATCH] mmc: dw_mmc: fix bug that cause 'Timeout sending command' Addy Ke
2015-02-09 4:51 ` Ulf Hansson
2015-02-09 6:56 ` Addy
2015-02-09 7:04 ` Jaehoon Chung
2015-02-09 9:17 ` addy ke
2015-02-09 7:25 ` [PATCH v2 0/2] about data busy Addy Ke
2015-02-09 7:25 ` [PATCH v2 1/2] mmc: dw_mmc: fix bug that cause 'Timeout sending command' Addy Ke
2015-02-09 10:01 ` Jaehoon Chung
2015-02-11 3:07 ` Addy [this message]
2015-02-10 15:22 ` Alim Akhtar
2015-02-11 2:57 ` Addy
2015-02-09 7:25 ` [PATCH v2 2/2] mmc: dw_mmc: Don't start command while data busy Addy Ke
2015-02-13 11:52 ` [PATCH v3 0/3] about " Addy Ke
2015-02-13 11:52 ` [PATCH v3 1/3] mmc: dw_mmc: update clock after host reach a stable voltage Addy Ke
2015-02-13 11:52 ` [PATCH v3 2/3] mmc: dw_mmc: fix bug that cause 'Timeout sending command' Addy Ke
2015-02-13 11:52 ` [PATCH v3 3/3] mmc: dw_mmc: Don't start command while data busy Addy Ke
2015-02-14 6:17 ` [PATCH v4 0/3] about " Addy Ke
2015-02-14 6:17 ` [PATCH v4 1/3] mmc: dw_mmc: update clock after host reach a stable voltage Addy Ke
2015-02-15 23:28 ` Alim Akhtar
2015-02-19 10:30 ` addy ke
2015-02-19 23:49 ` Doug Anderson
2015-02-20 0:02 ` Russell King - ARM Linux
2015-02-20 1:04 ` Doug Anderson
2015-02-20 19:05 ` Doug Anderson
2015-02-25 7:52 ` Alim Akhtar
2015-02-25 9:56 ` Jaehoon Chung
2015-02-25 21:05 ` Doug Anderson
2015-02-14 6:17 ` [PATCH v4 2/3] mmc: dw_mmc: fix bug that cause 'Timeout sending command' Addy Ke
2015-02-14 6:17 ` [PATCH v4 3/3] mmc: dw_mmc: Don't start command while data busy Addy Ke
2015-02-20 0:21 ` Doug Anderson
2015-02-15 11:41 ` [PATCH v4 0/3] about " Javier Martinez Canillas
2015-02-16 5:48 ` Jaehoon Chung
2015-02-16 11:09 ` Javier Martinez Canillas
2015-02-19 10:55 ` addy ke
2015-02-20 19:03 ` Doug Anderson
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