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HSI: omap_ssi_port: prepare start_tx/stop_tx for blocking pm_runtime calls 

ssi_start_tx and ssi_stop_tx may be called from atomic context. Once
pm_runtime_irq_safe() is removed for omap-ssi, this will fail, due
to blocking pm_runtime_*_sync() calls.

This fixes ssi_stop_tx by using non-sync API and ssi_start_tx by
using a worker thread.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Tested-by: Pavel Machek <pavel@ucw.cz>
hifive-unleashed-5.1
Sebastian Reichel 2016-05-11 20:33:45 +02:00
parent de5a3774dd
commit 7c5d81620e
2 changed files with 20 additions and 5 deletions
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2
drivers/hsi/controllers/omap_ssi.h
View File

@ -79,6 +79,7 @@ struct omap_ssm_ctx {
* @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
* @sys_mpu_enable: Context for the interrupt enable register for irq 0
* @sst: Context for the synchronous serial transmitter
* @ssr: Context for the synchronous serial receiver
@ -103,6 +104,7 @@ struct omap_ssi_port {
bool wktest:1; /* FIXME: HACK to be removed */
unsigned long flags;
unsigned int wk_refcount;
struct work_struct work;
/* OMAP SSI port context */
u32 sys_mpu_enable; /* We use only one irq */
struct omap_ssm_ctx sst;

23
drivers/hsi/controllers/omap_ssi_port.c
View File

@ -567,12 +567,22 @@ static int ssi_flush(struct hsi_client *cl)
return 0;
}
static void start_tx_work(struct work_struct *work)
{
struct omap_ssi_port *omap_port =
container_of(work, struct omap_ssi_port, work);
struct hsi_port *port = to_hsi_port(omap_port->dev);
struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */
writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
}
static int ssi_start_tx(struct hsi_client *cl)
{
struct hsi_port *port = hsi_get_port(cl);
struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
dev_dbg(&port->device, "Wake out high %d\n", omap_port->wk_refcount);
@ -581,10 +591,10 @@ static int ssi_start_tx(struct hsi_client *cl)
spin_unlock_bh(&omap_port->wk_lock);
return 0;
}
pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */
writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
spin_unlock_bh(&omap_port->wk_lock);
schedule_work(&omap_port->work);
return 0;
}
@ -604,9 +614,10 @@ static int ssi_stop_tx(struct hsi_client *cl)
return 0;
}
writel(SSI_WAKE(0), omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
pm_runtime_put_sync(omap_port->pdev); /* Release clocks */
spin_unlock_bh(&omap_port->wk_lock);
pm_runtime_put(omap_port->pdev); /* Release clocks */
return 0;
}
@ -1149,6 +1160,8 @@ static int ssi_port_probe(struct platform_device *pd)
omap_port->pdev = &pd->dev;
omap_port->port_id = port_id;
INIT_WORK(&omap_port->work, start_tx_work);
/* initialize HSI port */
port->async = ssi_async;
port->setup = ssi_setup;