[PATCH] OMAP: DSS: dispc: enable/disable clocks in error handler

There's no guarantee that the error handler worker thread
will run while the dispc clocks are on. Explicitly enable/disable
them.

Signed-off-by: Dima Zavin <redacted>
---
 drivers/video/omap2/dss/dispc.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/video/omap2/dss/dispc.c b/drivers/video/omap2/dss/dispc.c
index 62aa77c..2458248 100644
--- a/drivers/video/omap2/dss/dispc.c
+++ b/drivers/video/omap2/dss/dispc.c

@@ -3292,6 +3292,8 @@ static void dispc_error_worker(struct work_struct *work)
 	dispc.error_irqs = 0;
 	spin_unlock_irqrestore(&dispc.irq_lock, flags);
 
+	dispc_runtime_get();
+
 	if (errors & DISPC_IRQ_GFX_FIFO_UNDERFLOW) {
 		DSSERR("GFX_FIFO_UNDERFLOW, disabling GFX\n");
 		for (i = 0; i < omap_dss_get_num_overlays(); ++i) {

@@ -3478,6 +3480,8 @@ static void dispc_error_worker(struct work_struct *work)
 	dispc.irq_error_mask |= errors;
 	_omap_dispc_set_irqs();
 	spin_unlock_irqrestore(&dispc.irq_lock, flags);
+
+	dispc_runtime_put();
 }
 
 int omap_dispc_wait_for_irq_timeout(u32 irqmask, unsigned long timeout)

-- 
1.7.3.1

Hi,

On Monday 27 June 2011 10:31 AM, Dima Zavin wrote:

There's no guarantee that the error handler worker thread
will run while the dispc clocks are on. Explicitly enable/disable
them.

I agree with this.

Tomi,

We could get prevent scheduling of the error worker by registering 
omap_dispc_irq_handler() as an interrupt thread.

Archit

On Tue, 2011-06-28 at 09:19 -0700, Archit Taneja wrote:

Hi,

On Monday 27 June 2011 10:31 AM, Dima Zavin wrote:

quoted

There's no guarantee that the error handler worker thread
will run while the dispc clocks are on. Explicitly enable/disable
them.

I agree with this.

Yes, I think this patch is fine. I'll apply it to DSS tree.

Tomi,

We could get prevent scheduling of the error worker by registering 
omap_dispc_irq_handler() as an interrupt thread.

But then we would get extra latency on the interrupt handlers. I wanted
to keep handling DSS interrupts in interrupt context, because some use
cases may require very fast reaction to an interrupt.

 Tomi

Hi,

On Tuesday 28 June 2011 09:58 PM, Valkeinen, Tomi wrote:

On Tue, 2011-06-28 at 09:19 -0700, Archit Taneja wrote:

quoted

Hi,

On Monday 27 June 2011 10:31 AM, Dima Zavin wrote:

quoted

There's no guarantee that the error handler worker thread
will run while the dispc clocks are on. Explicitly enable/disable
them.

I agree with this.

Yes, I think this patch is fine. I'll apply it to DSS tree.

quoted

Tomi,

We could get prevent scheduling of the error worker by registering
omap_dispc_irq_handler() as an interrupt thread.

But then we would get extra latency on the interrupt handlers. I wanted
to keep handling DSS interrupts in interrupt context, because some use
cases may require very fast reaction to an interrupt.

Okay..we don't need to handle the errors in interrupt context..the 
request_threaded_irq() takes 2 functions I think, we could have have 
omap_dispc_irq_handler() as the primary handler, and the error_worker as 
the thread.

I think the change I'm just suggesting just leads to some beautification 
in the end :), we would still need to ensure that clocks are enabled in 
the error_worker path.

Archit