On Thursday 02 August 2012 22:46:18 Florian Tobias Schandinat wrote: > Hi Ondrej, > > On 08/02/2012 06:03 PM, Ondrej Zary wrote: > > Hello, > > I've got a Clevo M5x0V laptop which has VIA PM800 chipset (1106:3118) and > > 1280x768 LCD panel connected using VT1631L LVDS transmitter. There's a > > schematic of this laptop available on the web which shows that VT1631L's > > I2C port is not connected anywhere... > > > > viafb does not work properly - LCD panel (and backlight) is turned off > > upon module load and there's 640x480 signal on VGA connector (even when > > monitor was not connected during module load). > > Yes, that's the default (640x480-60 on the VGA output) that VIA selected > when they wrote the module. I tried to add some auto detect mechanism, > but I guess in your case it wouldn't help, even if it were complete. The > traditional way to use viafb is via module parameters as described in > Documentation/fb/viafb.txt > In your case something like this might work: > viafb_mode=1280x768 viafb_lcd_panel_id=3 viafb_active_dev=LCD Thank you very much, it works with these parameters! Looks like viafb can wake up the chip from S3, only the colors are messed up (X<->VT switch fixes that). > Additionally it might be required to add viafb_lcd_port with any of > DVP0, DVP1, DFP_HIGHLOW, DFP_HIGH, DFP_LOW. > > > Looking at the code, there's almost nothing for VT1631. What needs to be > > done in order for the LCD to work? Xorg seems to work using openchrome > > (but it is not able to restore the card on resume from S3): > > (II) CHROME(0): Unable to get panel size from EDID. Return code: 0 > > (II) CHROME(0): ViaPanelGetNativeModeFromScratchPad > > (II) CHROME(0): Native Panel Resolution is 1280x768 > > Interesting that they get the panel resolution from the scratch pad. The > official documentation does not contain any useful information about it > (and openchrome didn't work on any of my LCD devices that I tested, > hence I didn't care whether they did have any code in that area) > Maybe the above module parameters will help you, otherwise more > investigation will be required. Looking at openchrome and viafb code - the code is already present in viafb in fp_id_to_vindex() function in lcd.c. It even finds correct panel_id for me (3). But it looks like that the result is not used. -- Ondrej Zary -- 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
