Re: [PATCH v1, TRIVIAL] Fix pxafb nonstd field documentation and add errata info

[Petr Cvek <petr.cvek@tul.cz>]

Dne 20.8.2015 v 12:55 Tomi Valkeinen napsal(a):
> 
> 
> On 08/08/15 21:20, Petr Cvek wrote:
> 
>> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
>> index 2d98de5..8f485ec 100644
>> --- a/drivers/video/fbdev/Kconfig
>> +++ b/drivers/video/fbdev/Kconfig
>> @@ -1893,6 +1893,11 @@ config FB_PXA_OVERLAY
>>  	bool "Support PXA27x/PXA3xx Overlay(s) as framebuffer"
>>  	default n
>>  	depends on FB_PXA && (PXA27x || PXA3xx)
>> +	---help---
>> +	  Using the overlay 2 and YUV420 mode on a PXA27x C0 chip revision will
>> +	  hang the LCD until the next SoC restart (errata E24).
> 
> Shouldn't the driver handle this? It should not allow the combination to
> be used.
> 
>  Tomi
> 

Probably, but I don't know which revisions are OK and which are not. Errata document:

	Marvell® PXA270M Processor Specification Update
	MV-S900957-00

has only 3 revisions, but PXA Manual lists 6 (2.2.5.1 Processor ID Register) and one revision from errata is not shown in my PXA Manual. I can exclude mine revision (from "system_rev" variable), but there should be some warning somewhere in configuration.


BTW There is software workaround, but I was not able to set registers right (it requires to send some data through FIFO in different mode).

Petr