Hi, Hiremath, Vaibhav wrote: >> -----Original Message----- >> From: Taneja, Archit >> Sent: Monday, September 06, 2010 9:31 AM >> To: Hiremath, Vaibhav >> Cc: linux-omap@xxxxxxxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx >> Subject: RE: [PATCH 0/2] V4L/DVB: OMAP_VOUT: Allow omap_vout to build >> without VRFB >> >> Hi, >> >> Hiremath, Vaibhav wrote: >>>> -----Original Message----- >>>> From: Taneja, Archit >>>> Sent: Saturday, September 04, 2010 2:12 PM >>>> To: Hiremath, Vaibhav >>>> Cc: linux-omap@xxxxxxxxxxxxxxx; >>> linux-media@xxxxxxxxxxxxxxx; Taneja, >>>> Archit >>>> Subject: [PATCH 0/2] V4L/DVB: OMAP_VOUT: Allow omap_vout to build without >>>> VRFB >>>> >>>> This lets omap_vout driver build and run without VRFB. It works >>>> along the lines of the following patch series: >>>> OMAP: DSS2: OMAPFB: Allow FB_OMAP2 to build without VRFB >>>> https://patchwork.kernel.org/patch/105371/ >>>> >>>> A variable rotation_type is introduced in omapvideo_info like the >>>> way in omapfb_info to make both vrfb and non vrfb rotation possible. >>>> >>> [Hiremath, Vaibhav] Archit, >>> >>> Currently omap_vout driver only supports VRFB based rotation, it >>> doesn't support SDMA based rotation (unlike OMAPFB) and neither you patch >>> adds it. >> >> [Archit]The above description in the git commit is a mistake from my end. >> The main purpose of the patch is to get omap_vout running without VRFB. >> >> I am not sure if we need to enable SDMA rotation for V4L2 though, we >> would always have vrfb and tiler on omap3 and omap4 respectively. > [Hiremath, Vaibhav] No, for me SDMA based rotation doesn't > make sense, since SDMA rotation suffers from bandwidth issue. > On OMAPFB it has been observed that, DSS throws FIFO > underflow error very frequently in SDMA based rotation. > > >> >> How do you think things should be handled in the non vrfb case? Should we >> try to get rotation running or should the driver return an error if >> userspace tries to enable rotation in a non-vrfb mode? > [Hiremath, Vaibhav] We can handle this in 2 ways, > > - Driver can return -ERANGE error, in case of OMAP4 (or non-vrfb platform) > > - Driver can choose/fall-down 0 degree rotation gracefully > > As per V4L2 spec both options are acceptable. Thanks for the clarification. I will work on this change. Archit-- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
