When doing excessive hotplug, e.g., repeated insert/eject operations, the hardware may get confused to a point where no CMDTIMEOUT/CMDRESPEND interrupts are generated any more. As a result requests get stuck, e.g.:
[ 360.351562] INFO: task kworker/u:0:5 blocked for more than 120 seconds. [ 360.351562] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 360.359375] kworker/u:0 D c020c2b4 0 5 2 0x00000000 [ 360.367187] Backtrace: [ 360.367187] [<c020bfb0>] (schedule+0x0/0x340) from [<c020c480>] (schedule_timeout+0x20/0x190) [ 360.375000] r8:c702fd70 r7:00000002 r6:c702e000 r5:c702fdc4 r4:7fffffff [ 360.375000] r3:c701e040 [ 360.382812] [<c020c460>] (schedule_timeout+0x0/0x190) from [<c020be78>] (wait_for_common+0xc4/0x150) [ 360.390625] r6:c702e000 r5:c702fdc4 r4:7fffffff [ 360.390625] [<c020bdb4>] (wait_for_common+0x0/0x150) from [<c020bfac>] (wait_for_completion+0x18/0x1c) [ 360.398437] [<c020bf94>] (wait_for_completion+0x0/0x1c) from [<c0185590>] (mmc_wait_for_req+0x214/0x234) [ 360.406250] [<c018537c>] (mmc_wait_for_req+0x0/0x234) from [<c01889d0>] (mmc_sd_switch+0xfc/0x114) [ 360.414062] r7:c702fe4c r6:c702fe20 r5:c7179800 r4:00fffff0 [ 360.421875] [<c01888d4>] (mmc_sd_switch+0x0/0x114) from [<c0187f70>] (mmc_sd_setup_card+0x260/0x384) [ 360.429687] [<c0187d10>] (mmc_sd_setup_card+0x0/0x384) from [<c01885e0>] (mmc_sd_init_card+0x13c/0x1e0) [ 360.437500] [<c01884a4>] (mmc_sd_init_card+0x0/0x1e0) from [<c01887a8>] (mmc_attach_sd+0x124/0x1a8) [ 360.445312] r8:c02db404 r7:ffffff92 r6:c702ff34 r5:c6007da8 r4:c6007c00 [ 360.453125] [<c0188684>] (mmc_attach_sd+0x0/0x1a8) from [<c0185140>] (mmc_rescan+0x248/0x2f0) [ 360.460937] r5:c6007da8 r4:c6007c00 [ 360.468750] [<c0184ef8>] (mmc_rescan+0x0/0x2f0) from [<c00467f0>] (process_one_work+0x1ec/0x318) [ 360.476562] r7:c6007da8 r6:00000000 r5:c710ec00 r4:c701bde0 [ 360.484375] [<c0046604>] (process_one_work+0x0/0x318) from [<c0047fb0>] (worker_thread+0x1b0/0x2cc) [ 360.492187] [<c0047e00>] (worker_thread+0x0/0x2cc) from [<c004b338>] (kthread+0x8c/0x94) [ 360.500000] [<c004b2ac>] (kthread+0x0/0x94) from [<c0037fc4>] (do_exit+0x0/0x590) [ 360.507812] r7:00000013 r6:c0037fc4 r5:c004b2ac r4:c7021f00 This patch addresses this problem by introducing timeouts for outstanding interrupts. If a hardware interrupt is missing, a soft reset will be performed to bring the hardware back to a working state. Tested with the SDHI hardware block in sh7372. Signed-off-by: Arnd Hannemann <[email protected]> --- drivers/mmc/host/tmio_mmc.c | 81 ++++++++++++++++++++++++++++++++++++++++-- drivers/mmc/host/tmio_mmc.h | 7 ++++ 2 files changed, 84 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c index e7765a8..9a55afd 100644 --- a/drivers/mmc/host/tmio_mmc.c +++ b/drivers/mmc/host/tmio_mmc.c @@ -82,15 +82,60 @@ static void reset(struct tmio_mmc_host *host) msleep(10); } +static void tmio_mmc_reset_work(struct work_struct *work) +{ + struct tmio_mmc_host *host = container_of(work, struct tmio_mmc_host, + delayed_reset_work.work); + struct mmc_request *mrq; + unsigned long flags; + + spin_lock_irqsave(&host->lock, flags); + mrq = host->mrq; + + /* request already finished */ + if (!mrq + || time_is_after_jiffies(host->last_req_ts + + msecs_to_jiffies(2000))) { + spin_unlock_irqrestore(&host->lock, flags); + return; + } + + dev_warn(&host->pdev->dev, + "timeout waiting for hardware interrupt (CMD%u)\n", + mrq->cmd->opcode); + + if (host->data) + host->data->error = -ETIMEDOUT; + else if (host->cmd) + host->cmd->error = -ETIMEDOUT; + else + mrq->cmd->error = -ETIMEDOUT; + + host->cmd = NULL; + host->data = NULL; + host->mrq = NULL; + + spin_unlock_irqrestore(&host->lock, flags); + + reset(host); + + mmc_request_done(host->mmc, mrq); +} + static void tmio_mmc_finish_request(struct tmio_mmc_host *host) { struct mmc_request *mrq = host->mrq; + if (!mrq) + return; + host->mrq = NULL; host->cmd = NULL; host->data = NULL; + cancel_delayed_work(&host->delayed_reset_work); + mmc_request_done(host->mmc, mrq); } @@ -200,6 +245,7 @@ static void tmio_mmc_pio_irq(struct tmio_mmc_host *host) return; } +/* needs to be called with host->lock held */ static void tmio_mmc_do_data_irq(struct tmio_mmc_host *host) { struct mmc_data *data = host->data; @@ -254,10 +300,12 @@ static void tmio_mmc_do_data_irq(struct tmio_mmc_host *host) static void tmio_mmc_data_irq(struct tmio_mmc_host *host) { - struct mmc_data *data = host->data; + struct mmc_data *data; + spin_lock(&host->lock); + data = host->data; if (!data) - return; + goto out; if (host->chan_tx && (data->flags & MMC_DATA_WRITE)) { /* @@ -278,6 +326,8 @@ static void tmio_mmc_data_irq(struct tmio_mmc_host *host) } else { tmio_mmc_do_data_irq(host); } +out: + spin_unlock(&host->lock); } static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, @@ -286,9 +336,11 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, struct mmc_command *cmd = host->cmd; int i, addr; + spin_lock(&host->lock); + if (!host->cmd) { pr_debug("Spurious CMD irq\n"); - return; + goto out; } host->cmd = NULL; @@ -334,6 +386,9 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, tmio_mmc_finish_request(host); } +out: + spin_unlock(&host->lock); + return; } @@ -562,6 +617,12 @@ static void tmio_issue_tasklet_fn(unsigned long priv) static void tmio_tasklet_fn(unsigned long arg) { struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg; + unsigned long flags; + + spin_lock_irqsave(&host->lock, flags); + + if (!host->data) + goto out; if (host->data->flags & MMC_DATA_READ) dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->dma_sglen, @@ -571,6 +632,8 @@ static void tmio_tasklet_fn(unsigned long arg) DMA_TO_DEVICE); tmio_mmc_do_data_irq(host); +out: + spin_unlock_irqrestore(&host->lock, flags); } /* It might be necessary to make filter MFD specific */ @@ -694,6 +757,8 @@ static void tmio_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) if (host->mrq) pr_debug("request not null\n"); + host->last_req_ts = jiffies; + wmb(); host->mrq = mrq; if (mrq->data) { @@ -703,10 +767,14 @@ static void tmio_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) } ret = tmio_mmc_start_command(host, mrq->cmd); - if (!ret) + if (!ret) { + schedule_delayed_work(&host->delayed_reset_work, + msecs_to_jiffies(2000)); return; + } fail: + host->mrq = NULL; mrq->cmd->error = ret; mmc_request_done(mmc, mrq); } @@ -896,6 +963,11 @@ static int __devinit tmio_mmc_probe(struct platform_device *dev) if (ret) goto cell_disable; + spin_lock_init(&host->lock); + + /* Init delayed work for request timeouts */ + INIT_DELAYED_WORK(&host->delayed_reset_work, tmio_mmc_reset_work); + /* See if we also get DMA */ tmio_mmc_request_dma(host, pdata); @@ -936,6 +1008,7 @@ static int __devexit tmio_mmc_remove(struct platform_device *dev) mmc_remove_host(mmc); tmio_mmc_release_dma(host); free_irq(host->irq, host); + cancel_delayed_work_sync(&host->delayed_reset_work); if (cell->disable) cell->disable(dev); iounmap(host->ctl); diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h index 0fedc78..a40b477 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -12,6 +12,8 @@ #include <linux/highmem.h> #include <linux/interrupt.h> #include <linux/dmaengine.h> +#include <linux/workqueue.h> +#include <linux/spinlock.h> #define CTL_SD_CMD 0x00 #define CTL_ARG_REG 0x04 @@ -116,6 +118,11 @@ struct tmio_mmc_host { unsigned int dma_sglen; dma_cookie_t cookie; #endif + + /* Track lost interrupts */ + struct delayed_work delayed_reset_work; + spinlock_t lock; + unsigned long last_req_ts; }; #include <linux/io.h> -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
