Hi all, On Wed, Oct 15, 2008 at 01:48:26PM +0200, Michael 'Mickey' Lauer wrote: > Am Wednesday 15 October 2008 06:38:01 schrieb Mike (mwester): > > > FSO should switch the backlight control from the sysfs method to the > > > fbdev-ioctl method. It's backwards compatible to old kernels (which will > > > just backlight-blank) and future-compatible with kernels that add the > > > jbt6k74 notifier and glamo fb_blank() patches. > > Already done, thanks to a patch from Harald and some refactoring. > While doing this, I encountered a strange thing. One of my FreeRunners does > not recover from a BLANK ioctl anymore. The backlight turns on but the > display does not show any pixels. I have to reboot to make it work again. > Could that be connected to that infamous WSOD resume bug?
After a bit of debugging today on mickeys phone, it seems like the jbt6k74 fb_blank notifier is not to blame. the display still comes up white after fb_blank ioctl was issued. The real problem is in glamofb_blank() code (which I have written as part of the patchset regarding the measurements in this thread). All that we do in glamofb_blank() is to disable DCLK of the display controller. If I uncomment this code, the device properly comes back after the blanking. It really puzzles me what could be the cause of this. Only few GTA02 devices seem to show this behaviour. Mickey's device exhibiting this problem is a MP GTA02v6, just like other devices not exhibiting the problem. It is always reliable on a given device. Either it does always come back with a white screen, or it does always work. So it's unlikely timing related. There would be two questions for Smedia (who's the contact inside Openmoko to talk to them?): 1) Is there a certain condition when we can disable DCLK? Maybe stopping this clock is only valid in a certain state e.g. during vertical blank? What we want to do is to stop the glamo from producing any video output signal. 2) Did Openmoko ever use different silicon revisions of the Glamo 3362 for different production runs? -- - Harald Welte <[EMAIL PROTECTED]> http://openmoko.org/ ============================================================================ Software for the world's first truly open Free Software mobile phone
