HSI: omap_ssi_port: replace wkin_cken with atomic bitmap operations

This simplifies the code and avoids holding a spin_lock when
runtime pm calls are made. Once the irq_safe flag is removed
for omap_ssi's runtime pm, pm_runtime_get/put_sync can sleep,
which is a no-go while holding a spin_lock.

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 88a5239..6cdaad8 100644 (file)
--- a/drivers/hsi/controllers/omap_ssi.h
+++ b/drivers/hsi/controllers/omap_ssi.h
@@ -35,6 +35,8 @@
 #define SSI_MAX_GDD_LCH                8
 #define SSI_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
 
+#define SSI_WAKE_EN 0
+
 /**
  * struct omap_ssm_ctx - OMAP synchronous serial module (TX/RX) context
  * @mode: Bit transmission mode
@@ -75,7 +77,7 @@ struct omap_ssm_ctx {
  * @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
- * @wkin_cken: Keep track of clock references due to the incoming wake line
+ * @flags: flags to keep track of states
  * @wk_refcount: Reference count for output wake line
  * @sys_mpu_enable: Context for the interrupt enable register for irq 0
  * @sst: Context for the synchronous serial transmitter
@@ -99,7 +101,7 @@ struct omap_ssi_port {
        struct gpio_desc        *wake_gpio;
        struct tasklet_struct   pio_tasklet;
        bool                    wktest:1; /* FIXME: HACK to be removed */
-       bool                    wkin_cken:1; /* Workaround */
+       unsigned long           flags;
        unsigned int            wk_refcount;
        /* OMAP SSI port context */
        u32                     sys_mpu_enable; /* We use only one irq */

diff --git a/drivers/hsi/controllers/omap_ssi_port.c b/drivers/hsi/controllers/omap_ssi_port.c
index 9001b06..0d34523 100644 (file)
--- a/drivers/hsi/controllers/omap_ssi_port.c
+++ b/drivers/hsi/controllers/omap_ssi_port.c
@@ -751,10 +751,8 @@ static int ssi_release(struct hsi_client *cl)
                 * Drop the clock reference for the incoming wake line
                 * if it is still kept high by the other side.
                 */
-               if (omap_port->wkin_cken) {
+               if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
                        pm_runtime_put_sync(omap_port->pdev);
-                       omap_port->wkin_cken = 0;
-               }
                pm_runtime_get_sync(omap_port->pdev);
                /* Stop any SSI TX/RX without a client */
                ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
@@ -981,12 +979,8 @@ static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
                 * This workaround will avoid breaking the clock reference
                 * count when such a situation ocurrs.
                 */
-               spin_lock(&omap_port->lock);
-               if (!omap_port->wkin_cken) {
-                       omap_port->wkin_cken = 1;
+               if (!test_and_set_bit(SSI_WAKE_EN, &omap_port->flags))
                        pm_runtime_get_sync(omap_port->pdev);
-               }
-               spin_unlock(&omap_port->lock);
                dev_dbg(&ssi->device, "Wake in high\n");
                if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
                        writel(SSI_WAKE(0),
@@ -1000,12 +994,8 @@ static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
                                omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
                }
                hsi_event(port, HSI_EVENT_STOP_RX);
-               spin_lock(&omap_port->lock);
-               if (omap_port->wkin_cken) {
+               if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
                        pm_runtime_put_sync(omap_port->pdev);
-                       omap_port->wkin_cken = 0;
-               }
-               spin_unlock(&omap_port->lock);
        }
 
        return IRQ_HANDLED;