HSI: omap_ssi_port: switch to threaded pio irq

Move pio interrupt handler from tasklet into thread to
allow runtime_pm_get_sync calls without irq_safe being
set.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Tested-by: Pavel Machek <pavel@ucw.cz>

diff --git a/drivers/hsi/controllers/omap_ssi.h b/drivers/hsi/controllers/omap_ssi.h
index 5467f61e5086e95c4f7b0f78fc79a37e251199e5..99143f4f8837015a3a440034647bd85cd102388c 100644 (file)
--- a/drivers/hsi/controllers/omap_ssi.h
+++ b/drivers/hsi/controllers/omap_ssi.h
@@ -76,7 +76,6 @@ struct omap_ssm_ctx {
  * @irq: IRQ number
  * @wake_irq: IRQ number for incoming wake line (-1 if none)
  * @wake_gpio: GPIO number for incoming wake line (-1 if none)
- * @pio_tasklet: Bottom half for PIO transfers and events
  * @flags: flags to keep track of states
  * @wk_refcount: Reference count for output wake line
  * @work: worker for starting TX
@@ -100,7 +99,6 @@ struct omap_ssi_port {
        unsigned int            irq;
        int                     wake_irq;
        struct gpio_desc        *wake_gpio;
-       struct tasklet_struct   pio_tasklet;
        bool                    wktest:1; /* FIXME: HACK to be removed */
        unsigned long           flags;
        unsigned int            wk_refcount;

diff --git a/drivers/hsi/controllers/omap_ssi_port.c b/drivers/hsi/controllers/omap_ssi_port.c
index cc56d0ee82a22ab244130255a6f374c490782960..f62f0c482cea593c274a1184433378c9c63a02d7 100644 (file)
--- a/drivers/hsi/controllers/omap_ssi_port.c
+++ b/drivers/hsi/controllers/omap_ssi_port.c
@@ -877,7 +877,7 @@ static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue)
        u32 reg;
        u32 val;
 
-       spin_lock(&omap_port->lock);
+       spin_lock_bh(&omap_port->lock);
        msg = list_first_entry(queue, struct hsi_msg, link);
        if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) {
                msg->actual_len = 0;
@@ -909,7 +909,7 @@ static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue)
                                        (msg->ttype == HSI_MSG_WRITE))) {
                        writel(val, omap_ssi->sys +
                                        SSI_MPU_STATUS_REG(port->num, 0));
-                       spin_unlock(&omap_port->lock);
+                       spin_unlock_bh(&omap_port->lock);
 
                        return;
                }
@@ -925,12 +925,12 @@ static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue)
        writel_relaxed(reg, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
        writel_relaxed(val, omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
        list_del(&msg->link);
-       spin_unlock(&omap_port->lock);
+       spin_unlock_bh(&omap_port->lock);
        msg->complete(msg);
        ssi_transfer(omap_port, queue);
 }
 
-static void ssi_pio_tasklet(unsigned long ssi_port)
+static irqreturn_t ssi_pio_thread(int irq, void *ssi_port)
 {
        struct hsi_port *port = (struct hsi_port *)ssi_port;
        struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
@@ -941,37 +941,29 @@ static void ssi_pio_tasklet(unsigned long ssi_port)
        u32 status_reg;
 
        pm_runtime_get_sync(omap_port->pdev);
-       status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
-       status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
 
-       for (ch = 0; ch < omap_port->channels; ch++) {
-               if (status_reg & SSI_DATAACCEPT(ch))
-                       ssi_pio_complete(port, &omap_port->txqueue[ch]);
-               if (status_reg & SSI_DATAAVAILABLE(ch))
-                       ssi_pio_complete(port, &omap_port->rxqueue[ch]);
-       }
-       if (status_reg & SSI_BREAKDETECTED)
-               ssi_break_complete(port);
-       if (status_reg & SSI_ERROROCCURED)
-               ssi_error(port);
+       do {
+               status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
+               status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
 
-       status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
-       status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
-       pm_runtime_put_sync(omap_port->pdev);
+               for (ch = 0; ch < omap_port->channels; ch++) {
+                       if (status_reg & SSI_DATAACCEPT(ch))
+                               ssi_pio_complete(port, &omap_port->txqueue[ch]);
+                       if (status_reg & SSI_DATAAVAILABLE(ch))
+                               ssi_pio_complete(port, &omap_port->rxqueue[ch]);
+               }
+               if (status_reg & SSI_BREAKDETECTED)
+                       ssi_break_complete(port);
+               if (status_reg & SSI_ERROROCCURED)
+                       ssi_error(port);
 
-       if (status_reg)
-               tasklet_hi_schedule(&omap_port->pio_tasklet);
-       else
-               enable_irq(omap_port->irq);
-}
+               status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
+               status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
 
-static irqreturn_t ssi_pio_isr(int irq, void *port)
-{
-       struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
-
-       tasklet_hi_schedule(&omap_port->pio_tasklet);
-       disable_irq_nosync(irq);
+               /* TODO: sleep if we retry? */
+       } while (status_reg);
 
+       pm_runtime_put(omap_port->pdev);
        return IRQ_HANDLED;
 }
 
@@ -1023,10 +1015,8 @@ static int ssi_port_irq(struct hsi_port *port, struct platform_device *pd)
                return err;
        }
        omap_port->irq = err;
-       tasklet_init(&omap_port->pio_tasklet, ssi_pio_tasklet,
-                                                       (unsigned long)port);
-       err = devm_request_irq(&port->device, omap_port->irq, ssi_pio_isr,
-                                               0, "mpu_irq0", port);
+       err = devm_request_threaded_irq(&port->device, omap_port->irq, NULL,
+                               ssi_pio_thread, IRQF_ONESHOT, "SSI PORT", port);
        if (err < 0)
                dev_err(&port->device, "Request IRQ %d failed (%d)\n",
                                                        omap_port->irq, err);
@@ -1229,8 +1219,6 @@ static int ssi_port_remove(struct platform_device *pd)
 
        hsi_port_unregister_clients(port);
 
-       tasklet_kill(&omap_port->pio_tasklet);
-
        port->async     = hsi_dummy_msg;
        port->setup     = hsi_dummy_cl;
        port->flush     = hsi_dummy_cl;