Hello Lothar, On Tue, Jul 05, 2016 at 02:08:38PM +0200, Lothar Waßmann wrote: > On Tue, 5 Jul 2016 12:09:02 +0200 Uwe Kleine-König wrote: > > To reach my goal to keep the display on (showing whatever the bootloader > > initialized the display with) until the application starts caring for > > the display some driver must enable the regulator. The only candidates > > are the lcd driver (i.e. the patch under discussion) or some mechanism > > in the fb core. As there doesn't seem to be code in the core (and the > > core is dead?) what do you suggest me to do? > > > The simplefb driver (CONFIG_FB_SIMPLE) is designed for exactly this > purpose. If you rely on the bootloader's framebuffer being preserved > until your application starts without any driver that reserves the > corresponding memory, the framebuffer contents may be corrupted by the > booting kernel. I don't want to use the simplefb driver because the application makes use of planes which isn't supported by simplefb. To prevent the framebuffer being overwritten a chunk of memory at the end of RAM is reserved (similar to how simplefb is supposed to work). And even without my usecase of a persistent splash screen, if the fb is used as console, it should not be disabled either. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
