Hi Alim, On 02/11/2015 03:57 AM, Addy wrote: > > On 2015/02/10 23:22, Alim Akhtar wrote: >> Hi Addy, >> >> On Mon, Feb 9, 2015 at 12:55 PM, Addy Ke <addy.ke@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx> >>> --- >>> 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); >>> + >> Why 500 msec? > This timeout value is the same as mci_send_cmd: > static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg) > { > struct dw_mci *host = slot->host; > unsigned long timeout = jiffies + msecs_to_jiffies(500); > .... > } > > I have not clear that which is suitable. > Do you have any suggestion on it? >> >>> + 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); >>> + >> Why you need to reset all blocks? may be CTRL_RESET is good enough here. > I have tested on rk3288, if only reset ctroller, data busy bit will not > be cleaned,and we will still get > > "Timeout sending command". > >> >>> + /* 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); >>> >> hmm...I would suggest you to call dw_mci_wait_busy() from inside >> mci_send_cmd(), seems like dw_mmc hangs while sending update clock cmd >> in multiple cases.see [1] >> >> [1]: http://permalink.gmane.org/gmane.linux.kernel.mmc/31140 > I think this patch is more reasonable. > So I will resend patches based on this patch. > thank you! I have tested your patches instead [1] above and they do not solve my issue: Board: odroid-xu3/exynos5422/dw_mmc_250a. MMC card: absent, broken-cd quirk SD card: present System hangs during boot after few minutes kernel spits: [ 242.188098] INFO: task kworker/u16:1:50 blocked for more than 120 seconds. [ 242.193524] Not tainted 3.19.0-next-20150210-00002-gf96831b-dirty #3834 [ 242.200622] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 242.208422] kworker/u16:1 D c04766ac 0 50 2 0x00000000 [ 242.214756] Workqueue: kmmcd mmc_rescan [ 242.218553] [<c04766ac>] (__schedule) from [<c0476a58>] (schedule+0x34/0x98) [ 242.225591] [<c0476a58>] (schedule) from [<c047a4dc>] (schedule_timeout+0x110/0x164) [ 242.233302] [<c047a4dc>] (schedule_timeout) from [<c04774f0>] (wait_for_common+0xb8/0x14c) [ 242.241539] [<c04774f0>] (wait_for_common) from [<c0362138>] (mmc_wait_for_req+0x68/0x17c) [ 242.249861] [<c0362138>] (mmc_wait_for_req) from [<c03622cc>] (mmc_wait_for_cmd+0x80/0xa0) [ 242.258002] [<c03622cc>] (mmc_wait_for_cmd) from [<c0367e50>] (mmc_go_idle+0x78/0xf8) [ 242.265796] [<c0367e50>] (mmc_go_idle) from [<c0363e2c>] (mmc_rescan+0x280/0x314) [ 242.273253] [<c0363e2c>] (mmc_rescan) from [<c0034764>] (process_one_work+0x120/0x324) [ 242.281135] [<c0034764>] (process_one_work) from [<c00349cc>] (worker_thread+0x30/0x42c) [ 242.289194] [<c00349cc>] (worker_thread) from [<c003926c>] (kthread+0xd8/0xf4) [ 242.296389] [<c003926c>] (kthread) from [<c000e7c0>] (ret_from_fork+0x14/0x34) Just for record, Exynos4412/dw_mmc_240a with the same configuration (no MMC card, broken-cd) works OK without patches. Regards Andrzej >> >>> if (!clock) { >>> mci_writel(host, CLKENA, 0); >>> -- >>> 1.8.3.2 >>> >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >> >> > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-doc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html