From 5c935165da79644df90a647ecc140fb77b40dee5 Mon Sep 17 00:00:00 2001 From: Doug Anderson Date: Mon, 9 Mar 2015 16:18:21 -0700 Subject: [PATCH] mmc: dw_mmc: Add a timeout for sending CMD11 In the Designware databook's description of the "Voltage Switch Normal Scenario" it instructs us to set a timer and fail the voltage change if we don't see the voltage change interrupt within 2ms. Let's implement that. Without implementing this I have often been able to reproduce a hang while trying to send CMD11 on an rk3288-based board while constantly ejecting and inserting UHS cards. Signed-off-by: Doug Anderson Signed-off-by: Jaehoon Chung Signed-off-by: Ulf Hansson --- drivers/mmc/host/dw_mmc.c | 26 ++++++++++++++++++++++++++ include/linux/mmc/dw_mmc.h | 2 ++ 2 files changed, 28 insertions(+) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index f68ea4d..8e0836d3 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1021,6 +1021,15 @@ static void __dw_mci_start_request(struct dw_mci *host, dw_mci_start_command(host, cmd, cmdflags); + if (cmd->opcode == SD_SWITCH_VOLTAGE) { + /* + * Databook says to fail after 2ms w/ no response; give an + * extra jiffy just in case we're about to roll over. + */ + mod_timer(&host->cmd11_timer, + jiffies + msecs_to_jiffies(2) + 1); + } + if (mrq->stop) host->stop_cmdr = dw_mci_prepare_command(slot->mmc, mrq->stop); else @@ -2159,6 +2168,8 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id) /* Check volt switch first, since it can look like an error */ if ((host->state == STATE_SENDING_CMD11) && (pending & SDMMC_INT_VOLT_SWITCH)) { + del_timer(&host->cmd11_timer); + mci_writel(host, RINTSTS, SDMMC_INT_VOLT_SWITCH); pending &= ~SDMMC_INT_VOLT_SWITCH; dw_mci_cmd_interrupt(host, pending); @@ -2572,6 +2583,18 @@ ciu_out: return ret; } +static void dw_mci_cmd11_timer(unsigned long arg) +{ + struct dw_mci *host = (struct dw_mci *)arg; + + if (host->state != STATE_SENDING_CMD11) + dev_info(host->dev, "Unexpected CMD11 timeout\n"); + + host->cmd_status = SDMMC_INT_RTO; + set_bit(EVENT_CMD_COMPLETE, &host->pending_events); + tasklet_schedule(&host->tasklet); +} + #ifdef CONFIG_OF static struct dw_mci_of_quirks { char *quirk; @@ -2746,6 +2769,9 @@ int dw_mci_probe(struct dw_mci *host) } } + setup_timer(&host->cmd11_timer, + dw_mci_cmd11_timer, (unsigned long)host); + host->quirks = host->pdata->quirks; spin_lock_init(&host->lock); diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h index 471fb31..9efc567 100644 --- a/include/linux/mmc/dw_mmc.h +++ b/include/linux/mmc/dw_mmc.h @@ -202,6 +202,8 @@ struct dw_mci { int irq; int sdio_id0; + + struct timer_list cmd11_timer; }; /* DMA ops for Internal/External DMAC interface */ -- 2.7.4