iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

HSI: omap_ssi_port: replace wkin_cken with atomic bitmap operations

Browse Source 
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>
This commit is contained in:
Sebastian Reichel 2016-04-30 17:11:54 +02:00
parent cb70e4c1bc
commit 2083057aac
2 changed files with 7 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/hsi/controllers/omap_ssi.h
View File

@ -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 */

16
drivers/hsi/controllers/omap_ssi_port.c
View File

@ -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;