Commit ee157abe authored by Ludovic Barre's avatar Ludovic Barre Committed by Ulf Hansson
Browse files

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: default avatarLudovic 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: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent d0052ad9

drivers/mmc/host/mmci.c

+40 −6
Original line number Diff line number Diff line
@@ -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;

			}

		}



		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)
@@ -2063,7 +2096,8 @@ static int mmci_probe(struct amba_device *dev, 
			goto clk_disable;

	}



	ret = devm_request_irq(&dev->dev, dev->irq[0], mmci_irq, IRQF_SHARED,

	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;

drivers/mmc/host/mmci.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

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