[PATCH v2 1/8] mmc: sdhci: Get rid of finish_tasklet

Faiz Abbas
2019-02-15T19:20:26Z

sdhci.c has two bottom halves implemented. A threaded_irq for handling
card insert/remove operations and a tasklet for finishing mmc requests.
With the addition of external dma support, dmaengine APIs need to
terminate in non-atomic context before unmapping the dma buffers.

To facilitate this, remove the finish_tasklet and move the call of
sdhci_request_done() to the threaded_irq() callback. Also move the
interrupt result variable to sdhci_host so it can be populated from
anywhere inside the sdhci_irq handler.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
---
drivers/mmc/host/sdhci.c | 43 +++++++++++++++-------------------------
drivers/mmc/host/sdhci.h | 2 +-
2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index eba9bcc92ad3..20ed09b896d7 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1232,7 +1232,7 @@ static void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)

WARN_ON(i >= SDHCI_MAX_MRQS);

- tasklet_schedule(&host->finish_tasklet);
+ host->result = IRQ_WAKE_THREAD;
}

static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
@@ -2705,14 +2705,6 @@ static bool sdhci_request_done(struct sdhci_host *host)
return false;
}

-static void sdhci_tasklet_finish(unsigned long param)
-{
- struct sdhci_host *host = (struct sdhci_host *)param;
-
- while (!sdhci_request_done(host))
- ;
-}
-
static void sdhci_timeout_timer(struct timer_list *t)
{
struct sdhci_host *host;
@@ -2995,11 +2987,12 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)

static irqreturn_t sdhci_irq(int irq, void *dev_id)
{
- irqreturn_t result = IRQ_NONE;
struct sdhci_host *host = dev_id;
u32 intmask, mask, unexpected = 0;
int max_loops = 16;

+ host->result = IRQ_NONE;
+
spin_lock(&host->lock);

if (host->runtime_suspended && !sdhci_sdio_irq_enabled(host)) {
@@ -3009,7 +3002,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)

intmask = sdhci_readl(host, SDHCI_INT_STATUS);
if (!intmask || intmask == 0xffffffff) {
- result = IRQ_NONE;
+ host->result = IRQ_NONE;
goto out;
}

@@ -3054,7 +3047,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)

host->thread_isr |= intmask & (SDHCI_INT_CARD_INSERT |
SDHCI_INT_CARD_REMOVE);
- result = IRQ_WAKE_THREAD;
+ host->result = IRQ_WAKE_THREAD;
}

if (intmask & SDHCI_INT_CMD_MASK)
@@ -3074,7 +3067,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
(host->ier & SDHCI_INT_CARD_INT)) {
sdhci_enable_sdio_irq_nolock(host, false);
host->thread_isr |= SDHCI_INT_CARD_INT;
- result = IRQ_WAKE_THREAD;
+ host->result = IRQ_WAKE_THREAD;
}

intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE |
@@ -3087,8 +3080,8 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
sdhci_writel(host, intmask, SDHCI_INT_STATUS);
}
cont:
- if (result == IRQ_NONE)
- result = IRQ_HANDLED;
+ if (host->result == IRQ_NONE)
+ host->result = IRQ_HANDLED;

intmask = sdhci_readl(host, SDHCI_INT_STATUS);
} while (intmask && --max_loops);
@@ -3101,7 +3094,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
sdhci_dumpregs(host);
}

- return result;
+ return host->result;
}

static irqreturn_t sdhci_thread_irq(int irq, void *dev_id)
@@ -3131,6 +3124,12 @@ static irqreturn_t sdhci_thread_irq(int irq, void *dev_id)
spin_unlock_irqrestore(&host->lock, flags);
}

+ if (!isr) {
+ do {
+ isr = !sdhci_request_done(host);
+ } while (isr);
+ }
+
return isr ? IRQ_HANDLED : IRQ_NONE;
}

@@ -4212,12 +4211,6 @@ int __sdhci_add_host(struct sdhci_host *host)
struct mmc_host *mmc = host->mmc;
int ret;

- /*
- * Init tasklets.
- */
- tasklet_init(&host->finish_tasklet,
- sdhci_tasklet_finish, (unsigned long)host);
-
timer_setup(&host->timer, sdhci_timeout_timer, 0);
timer_setup(&host->data_timer, sdhci_timeout_data_timer, 0);

@@ -4230,7 +4223,7 @@ int __sdhci_add_host(struct sdhci_host *host)
if (ret) {
pr_err("%s: Failed to request IRQ %d: %d\n",
mmc_hostname(mmc), host->irq, ret);
- goto untasklet;
+ return ret;
}

ret = sdhci_led_register(host);
@@ -4263,8 +4256,6 @@ int __sdhci_add_host(struct sdhci_host *host)
sdhci_writel(host, 0, SDHCI_INT_ENABLE);
sdhci_writel(host, 0, SDHCI_SIGNAL_ENABLE);
free_irq(host->irq, host);
-untasklet:
- tasklet_kill(&host->finish_tasklet);

return ret;
}
@@ -4326,8 +4317,6 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
del_timer_sync(&host->timer);
del_timer_sync(&host->data_timer);

- tasklet_kill(&host->finish_tasklet);
-
if (!IS_ERR(mmc->supply.vqmmc))
regulator_disable(mmc->supply.vqmmc);

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 6cc9a3c2ac66..624d5aa01995 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -554,7 +554,7 @@ struct sdhci_host {

unsigned int desc_sz; /* ADMA descriptor size */

- struct tasklet_struct finish_tasklet; /* Tasklet structures */
+ irqreturn_t result; /* Result of IRQ handler */

struct timer_list timer; /* Timer for timeouts */
struct timer_list data_timer; /* Timer for data timeouts */
--
2.19.2