Op 14 mei 2010, om 12:58 heeft Nishanth Menon het volgende geschreven: > Koen Kooi had written, on 05/14/2010 05:39 AM, the following: >> Op 14 mei 2010, om 12:03 heeft Guruswamy, Senthilvadivu het volgende geschreven: >>> >>>> -----Original Message----- >>>> From: Tomi Valkeinen [mailto:tomi.valkeinen@xxxxxxxxx] Sent: Friday, May 14, 2010 12:54 PM >>>> To: Guruswamy, Senthilvadivu >>>> Cc: linux-omap@xxxxxxxxxxxxxxx; linux-fbdev@xxxxxxxxxxxxxxx; tony@xxxxxxxxxxx; Hiremath, Vaibhav >>>> Subject: Re: [PATCH v2 0/2] DSS2:Allow FB to build without VRFB >>>> >>>> Hi, >>>> >>>> On Thu, 2010-05-13 at 17:20 +0200, ext Senthilvadivu Guruswamy wrote: >>>>> From: Senthilvadivu Guruswamy <svadivu@xxxxxx> >>>>> >>>>> Hi all, >>>>> >>>>> This patch series replaces the patch "DSS2 Include VRFB into omap2-3build only" >>>>> Thanks for the review comments. >>>>> The intent of this series is to split the patch into 2 logical >>>>> patches and also to incorporate the comments on multi-omap build. >>>>> >>>>> In this series, Kconfig is changed to have OMAP2_VRFB depend on ARCH_OMAP2 and ARCH_OMAP3. >>>>> This change takes care of the multi-omap builds. >>>>> This patch would allow successful build of omap_4430sdp_defconfig when OMAP2_DSS and FB_OMAP2 is enabled from menuconfig. >>>>> >>>>> For verification: Generated the .config on omap3_defconfig with DSS >>>>> and FB enabled. Generated .config is same with and without >>>> the patch. >>>>> List of Changed Files: >>>>> arch/arm/plat-omap/include/plat/vrfb.h >>>>> drivers/video/omap2/Kconfig >>>>> drivers/video/omap2/omapfb/Kconfig >>>> The patch set makes VRFB optional. What happens if VRFB is turned off, >>>> and the user uses VRFB for a framebuffer? >>> [Senthil] This patch keeps VRFB=y for ARCH_OMAP2 and ARCH_OMAP3. >>> User would have got an option to turn it OFF if it had appeared in the menuconfig selections. I did not give that option in menuconfig explicitly. ie config OMAP2_VRFB >>> bool <No name given here> >>> >>> Suppose on a build the user deliberately gives "CONFIG_OMAP2_VRFB not set", >>> then VRFB functions are made as empty functions by the compiler. >>> >>> This is fine as long as the user does not say omapfb.vrfb=1. >>> >>> But if the user sets omapfb.vrfb=1, then it is a wrong usage of the bootargs >>> as he has already deliberately changed the defconfig to say "VRFB not set". >>> >>> The result of his experiment: No bootup on the board as the vaddr of VRFB is populated nor of the normal RAM buffer. >> And that is unacceptable when working with customers (or users in the open > >source world). Instead of the kernel hacker spending an hour or 2 on a proper > > solution we now need to waste a whole lot more time supporting customers who > > pass vrfb in bootargs without knowing that it's turned off in the kernel. > But why use bootargs? Because (for some unknown reason) you can't toggle vrfb at runtime. If you realize you need rotation you need to reboot. I guess it's because the memory layout for vrfb is completely different, but again, I'm not a kernel hacker :) regards, Koen-- 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
