Thanks, Vaibhav Hiremath > -----Original Message----- > From: Tomi Valkeinen [mailto:tomi.valkeinen@xxxxxxxxx] > Sent: Friday, March 13, 2009 2:01 PM > To: Hiremath, Vaibhav > Cc: linux-omap@xxxxxxxxxxxxxxx > Subject: RE: Suspend/Resume support with Omap2fb > > Hi, > > On Thu, 2009-03-12 at 19:26 +0100, ext Hiremath, Vaibhav wrote: > > Hi, > > > > Finally I could able to find the root-cause, actually some of the > previous observations miss-led me to dig into power management, > suspend/resume path and clock structure. But after bit debugging and > with the help of Sanjeev, we got the rid of it. > > > > The issue is with DSS2 library, inside function > "dpi_display_suspend". It calls dispc_enable_lcd_out(0), but doesn't > wait till the frame-done interrupt. And due to this I was getting > some abrupt behavior in suspend/resume path. > > Actually in the beginning I overlooked legacy frame-buffer driver, > which handles this scenario perfectly. > > dispc_enable_lcd_out(0) waits for FRAMEDONE. Please use the latest > DSS2 > version from my git repository =). > [Hiremath, Vaibhav] Ohhh great, but I think yesterday only I pulled changes from your repository, and it was not there. Ok, but it's great that you merged the change. > Tomi > > > > > For Display sub-system we have 2 interface clocks coming, L3_ICLK > and L4_ICLK. Out of these, L4_ICLK goes to Display register access > and L3_ICLK goes to DMA register. In our suspend call we are > disabling clocks for L3_ICLK (we don't control L4_ICLK), and due to > this L4_ICLK stays attached with GFX. You will only be able to find > out this by looking to CM_CLKSTST_DSS.CLKACTIVITY_DSS, which is set > 1 and indicates some interface clock is still active in DSS domain. > > > > Below is the patch which will explain the change > > > > > > +#include <linux/completion.h> > > +#include <linux/jiffies.h> > > > > +static void dpi_display_isr(void *arg, unsigned int irqstatus) > > +{ > > + struct omap_display *display = (struct omap_display *)arg; > > + > > + complete(&display->frame_done); > > +} > > > > static int dpi_display_suspend(struct omap_display *display) > > { > > + void *handle = NULL; > > + > > if (display->state != OMAP_DSS_DISPLAY_ACTIVE) > > return -EINVAL; > > > > if (display->panel->suspend) > > display->panel->suspend(display); > > > > + /* > > + * Wait for frame done interrupt > > + */ > > + handle = omap_dispc_register_isr(dpi_display_isr, display, > > + DISPC_IRQ_FRAMEDONE); > > + if (!handle) > > + return -EINVAL; > > + > > + init_completion(&display->frame_done); > > + > > dispc_enable_lcd_out(0); > > + if (!wait_for_completion_timeout(&display->frame_done, > > + msecs_to_jiffies(500))) { > > + printk("timeout waiting for FRAME DONE\n"); > > + } > > > > Still I need to test this thoroughly, I may hit some another issue > (Already I am seeing some crashes also when off state is enabled). I > will create consolidated patch for this and will submit to list. > > > > Thanks, > > Vaibhav Hiremath > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
