Hi InKi, Thanks for your reply. On Wed, Jun 30, 2010 at 12:36 PM, InKi Dae <daeinki@xxxxxxxxx> wrote: > Hi Jaya, > > 2010/6/30 Jaya Kumar <jayakumar.lkml@xxxxxxxxx>: >> 2010/6/29 InKi Dae <inki.dae@xxxxxxxxxxx>: >>> CPU interface needs cs, wr setup, wr act and hold delay. >>> I added some members for them to common framework. >> >> Hi InKi Dae, >> >> The patch looks interesting. Could you help us understand more about >> it from a big picture perspective? ie: how is this "cpu interface" >> used? I think fb_var_screeninfo is intended to be a very generic data >> structure and since it is exposed to userspace we should be cautious >> about what we add to it. I didn't understand the purpose of exposing >> cs, wr setup, wr act and hold delay to userspace. > > in case of lcd panel with cpu interface, it could get screen data > through arm core > or display controller supporting cpu interface mode. > display controller of s5pv210 chip can create cpu interface signal according to > cs, wr setup, wr act and hold time setting. > the reason I added cpu timing variables to fb_var_screeninfo is for using common > framework when setting them to the display controller as cpu timing info. > please, see [PATCH 2/3], s3c_fb_set_timing function part. > > and cpu timing could be adjusted by user through fb_var_screeninfo, > for this, suitable checking should be considered at machine specific > fb_check_var func. > also you can see that through [PATCH 2/3], s3c_fb_check_var. I'm still having difficulty understanding this. I guess what I am asking is why do these new variables "cs, wr setup, wr act and hold time setting", have to be in fb_var_screeninfo which is a generic platform/implementation independent structure exposed to userspace? If I've understood things correctly, the variables themselves, eg: wr setup seem to be specific to this implementation rather than being generic like the other members of fb_var_sreeninfo. Have you considered an alternative way by which you can achieve the desired functionality. Also, I'm confused when you say "cpu timing" could be adjusted by user through fb_var_screeninfo. Could you elaborate on that? I haven't read through the remaining part of the message about mipi-dsi issues, I'm hoping developers who have implemented the other MIPI-DSI implementations in fbdev could chime in. Thanks, jaya -- 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
