Add a timeout for busydetect IRQs using a delayed work.
It might happen (and does happen) on Ux500 that the first
busy detect IRQ appears and not the second one. This will
make the host hang indefinitely waiting for the second
IRQ to appear.
Fire a delayed work after 10ms and re-engage the command
IRQ so the transaction finishes: we are certainly done
at this point, or we will catch an error in the status
register.
This makes the eMMC work again on Skomer.
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v2->v3:
- Rebased.
ChangeLog v1->v2:
- No changes
---
drivers/mmc/host/mmci.c | 23 +++++++++++++++++++++++
drivers/mmc/host/mmci.h | 1 +
2 files changed, 24 insertions(+)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 05b8fad26c10..7e40b8f2dbf3 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -37,6 +37,7 @@
#include <linux/pinctrl/consumer.h>
#include <linux/reset.h>
#include <linux/gpio/consumer.h>
+#include <linux/workqueue.h>
#include <asm/div64.h>
#include <asm/io.h>
@@ -741,6 +742,8 @@ static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);
writel(host->variant->busy_detect_mask, base + MMCICLEAR);
host->busy_state = MMCI_BUSY_WAITING_FOR_END_IRQ;
+ schedule_delayed_work(&host->busy_timeout_work,
+ msecs_to_jiffies(10));
} else {
dev_dbg(mmc_dev(host->mmc),
"lost busy status when waiting for busy start IRQ\n");
@@ -752,6 +755,7 @@ static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
if (status & host->variant->busy_detect_flag) {
host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);
writel(host->variant->busy_detect_mask, base + MMCICLEAR);
+ cancel_delayed_work_sync(&host->busy_timeout_work);
ux500_busy_clear_mask_done(host);
} else {
dev_dbg(mmc_dev(host->mmc),
@@ -1487,6 +1491,22 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
}
}
+/*
+ * This busy timeout worker is used to "kick" the command IRQ if a
+ * busy detect IRQ fails to appear in reasonable time. Only used on
+ * variants with busy detection IRQ delivery.
+ */
+static void busy_timeout_work(struct work_struct *work)
+{
+ struct mmci_host *host =
+ container_of(work, struct mmci_host, busy_timeout_work.work);
+ u32 status;
+
+ dev_dbg(mmc_dev(host->mmc), "timeout waiting for busy IRQ\n");
+ status = readl(host->base + MMCISTATUS);
+ mmci_cmd_irq(host, host->cmd, status);
+}
+
static int mmci_get_rx_fifocnt(struct mmci_host *host, u32 status, int remain)
{
return remain - (readl(host->base + MMCIFIFOCNT) << 2);
@@ -2300,6 +2320,9 @@ static int mmci_probe(struct amba_device *dev,
goto clk_disable;
}
+ if (host->variant->busy_detect && host->ops->busy_complete)
+ INIT_DELAYED_WORK(&host->busy_timeout_work, busy_timeout_work);
+
writel(MCI_IRQENABLE | variant->start_err, host->base + MMCIMASK0);
amba_set_drvdata(dev, mmc);
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 12a7bbd3ce26..95d3d0a6049b 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -451,6 +451,7 @@ struct mmci_host {
void *dma_priv;
s32 next_cookie;
+ struct delayed_work busy_timeout_work;
};
#define dma_inprogress(host) ((host)->dma_in_progress)
--
2.40.1
