Re: Fix for dispc's error "omapfb omapfb: irq error status 4020"

[Koen Kooi]

Op 7 nov 2008, om 21:55 heeft Rick Bronson het volgende geschreven:

Folks,

 Please take a look at this change to drivers/video/omap/dispc.c.  It
addresses a problem seen on some boots of OMAP's.  On about 1 in 30
boots one gets an endless stream of interrupts from the
DISPC_IRQ_SYNC_LOST bit in the DISPC_IRQSTATUS register.  The
following messages are printed.

omapfb omapfb: irq error status 4020

 The correct solution to this problem is to perform a "soft reset"
but that requires a bit of re-architecturing of the code as the init
routine would have to be split up, etc.  See the OMAP pdf, search for
"To clear a synchronization lost interrupt".

 This patch allows the above error message to get printed once and
then disables further DISPC_IRQ_SYNC_LOST interrups.

 Comments?

regards,

Koen

I can trigger this with all boots using Tomi's DSS patches on a rev C prototype beagle (ES3.0 3530), so those probably need a similar patch :)

 Thanks,

Rick


@@ -157,7 +157,7 @@ struct resmap {

#define MAX_IRQ_HANDLERS            4

-static struct {
+static struct omapfb_dispc {
        void __iomem    *base;

        struct omapfb_mem_desc  mem_desc;
@@ -169,6 +169,7 @@ static struct {

        int             ext_mode;

+       u32     irq_error_mask;  /* mask used for errors */
        struct {
                u32     irq_mask;
                void    (*callback)(void *);
@@ -812,16 +813,16 @@ static void set_lcd_timings(void)
        panel->pixel_clock = fck / lck_div / pck_div / 1000;
}

-static void recalc_irq_mask(void)
+static void recalc_irq_mask(struct omapfb_dispc *p_dispc)
{
        int i;
-       unsigned long irq_mask = DISPC_IRQ_MASK_ERROR;
+       unsigned long irq_mask = p_dispc->irq_error_mask;

        for (i = 0; i < MAX_IRQ_HANDLERS; i++) {
-               if (!dispc.irq_handlers[i].callback)
+               if (!p_dispc->irq_handlers[i].callback)
                        continue;

-               irq_mask |= dispc.irq_handlers[i].irq_mask;
+               irq_mask |= p_dispc->irq_handlers[i].irq_mask;
        }

        enable_lcd_clocks(1);
@@ -843,7 +844,7 @@ int omap_dispc_request_irq(unsigned long
                dispc.irq_handlers[i].irq_mask = irq_mask;
                dispc.irq_handlers[i].callback = callback;
                dispc.irq_handlers[i].data = data;
-               recalc_irq_mask();
+               recalc_irq_mask(&dispc);

                return 0;
        }
@@ -863,7 +864,7 @@ void omap_dispc_free_irq(unsigned long i
                        dispc.irq_handlers[i].irq_mask = 0;
                        dispc.irq_handlers[i].callback = NULL;
                        dispc.irq_handlers[i].data = NULL;
-                       recalc_irq_mask();
+                       recalc_irq_mask(&dispc);
                        return;
                }
        }
@@ -884,6 +885,10 @@ static irqreturn_t omap_dispc_irq_handle
                complete(&dispc.frame_done);

        if (stat & DISPC_IRQ_MASK_ERROR) {

+                       recalc_irq_mask(&dispc);
+                       }
                if (printk_ratelimit()) {
                        dev_err(dispc.fbdev->dev, "irq error status %04x\n",
                                stat & 0x7fff);
@@ -897,6 +902,7 @@ static irqreturn_t omap_dispc_irq_handle
        }

        dispc_write_reg(DISPC_IRQSTATUS, stat);
+       stat = dispc_read_reg(DISPC_IRQSTATUS);

        enable_lcd_clocks(0);

@@ -1432,7 +1438,8 @@ static int omap_dispc_init(struct omapfb
        l = dispc_read_reg(DISPC_IRQSTATUS);
        dispc_write_reg(DISPC_IRQSTATUS, l);

-       recalc_irq_mask();
+       dispc.irq_error_mask = DISPC_IRQ_MASK_ERROR;  /* init error mask */
+       recalc_irq_mask(&dispc);

        if ((r = request_irq(INT_24XX_DSS_IRQ, omap_dispc_irq_handler,
                           0, MODULE_NAME, fbdev)) < 0) {

--

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--- linux-omap-2.6/drivers/video/omap/dispc.c.~1~ 2008-11-04 14:23:38.000000000 -0800 +++ linux-omap-2.6/drivers/video/omap/dispc.c 2008-11-07 12:34:54.000000000 -0800 + if (stat & DISPC_IRQ_SYNC_LOST) { /* only allow sync lost once or we end up... */ + dispc.irq_error_mask &= ~DISPC_IRQ_SYNC_LOST; /* with a barrage of interrupts */ To unsubscribe from this list: send the line "unsubscribe linux- omap" in

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