mmc: mmci: add threaded irq to abort DPSM of non-functional state
The stm32_sdmmc variant has build-in support for datatimeout for R1B
requests. If a corresponding IRQ is raised, this triggers the DPSM to stay
busy and remains in a non-functional state. Only a reset can bring it back
to a functional state.
Because a reset must be issued from non-atomic context, let's defer this to
be managed from a threaded IRQ handler. Besides the reset, the threaded
handler also calls mmc_request_done(), to finally complete the request.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Link: https://lore.kernel.org/r/20191211133934.16932-1-ludovic.Barre@st.com
[Ulf: A few minor updates to the changelog/comments]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 39bc4d9..b2b6daf 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1321,6 +1321,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
} else if (host->variant->busy_timeout && busy_resp &&
status & MCI_DATATIMEOUT) {
cmd->error = -ETIMEDOUT;
+ host->irq_action = IRQ_WAKE_THREAD;
} else {
cmd->resp[0] = readl(base + MMCIRESPONSE0);
cmd->resp[1] = readl(base + MMCIRESPONSE1);
@@ -1339,7 +1340,10 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
return;
}
}
- mmci_request_end(host, host->mrq);
+
+ if (host->irq_action != IRQ_WAKE_THREAD)
+ mmci_request_end(host, host->mrq);
+
} else if (sbc) {
mmci_start_command(host, host->mrq->cmd, 0);
} else if (!host->variant->datactrl_first &&
@@ -1532,9 +1536,9 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
{
struct mmci_host *host = dev_id;
u32 status;
- int ret = 0;
spin_lock(&host->lock);
+ host->irq_action = IRQ_HANDLED;
do {
status = readl(host->base + MMCISTATUS);
@@ -1574,12 +1578,41 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
if (host->variant->busy_detect_flag)
status &= ~host->variant->busy_detect_flag;
- ret = 1;
} while (status);
spin_unlock(&host->lock);
- return IRQ_RETVAL(ret);
+ return host->irq_action;
+}
+
+/*
+ * mmci_irq_thread() - A threaded IRQ handler that manages a reset of the HW.
+ *
+ * A reset is needed for some variants, where a datatimeout for a R1B request
+ * causes the DPSM to stay busy (non-functional).
+ */
+static irqreturn_t mmci_irq_thread(int irq, void *dev_id)
+{
+ struct mmci_host *host = dev_id;
+ unsigned long flags;
+
+ if (host->rst) {
+ reset_control_assert(host->rst);
+ udelay(2);
+ reset_control_deassert(host->rst);
+ }
+
+ spin_lock_irqsave(&host->lock, flags);
+ writel(host->clk_reg, host->base + MMCICLOCK);
+ writel(host->pwr_reg, host->base + MMCIPOWER);
+ writel(MCI_IRQENABLE | host->variant->start_err,
+ host->base + MMCIMASK0);
+
+ host->irq_action = IRQ_HANDLED;
+ mmci_request_end(host, host->mrq);
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ return host->irq_action;
}
static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
@@ -2063,8 +2096,9 @@ static int mmci_probe(struct amba_device *dev,
goto clk_disable;
}
- ret = devm_request_irq(&dev->dev, dev->irq[0], mmci_irq, IRQF_SHARED,
- DRIVER_NAME " (cmd)", host);
+ ret = devm_request_threaded_irq(&dev->dev, dev->irq[0], mmci_irq,
+ mmci_irq_thread, IRQF_SHARED,
+ DRIVER_NAME " (cmd)", host);
if (ret)
goto clk_disable;
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 12d4ed8..be6cd1d 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -411,6 +411,7 @@ struct mmci_host {
struct timer_list timer;
unsigned int oldstat;
+ u32 irq_action;
/* pio stuff */
struct sg_mapping_iter sg_miter;