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mmc: mmci: add threaded irq to abort DPSM of non-functional state

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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>
This commit is contained in:
Ludovic Barre 2019-12-11 14:39:34 +01:00 committed by Ulf Hansson
parent d0052ad90e
commit ee157abebc
2 changed files with 41 additions and 6 deletions
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46
drivers/mmc/host/mmci.c
View file

@ -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;

1
drivers/mmc/host/mmci.h
View file

@ -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;