Hi Rob Clark, I'm sorry for that my mean didn't convey to you so I condensed that into brief again. I know drm_fb_helper_single_fb_probe() calls register_framebuffer(), My question is that it's right way to call only drm_fb_helper_set_par() if fb_helper->funcs->fb_probe() returns nonzero. In this case, if fb_helper->funcs->fb_probe() returns zero then register_framebuffer() isn't called and this means linux framebuffer isn't used anymore. one more question, otherwise if it uses drm based framebuffer, register_framebuffer() should be called necessarily at booting time? Thank you. Rob Clark 쓴 글: > fwiw, drm_fb_helper_single_fb_probe() calls register_framebuffer() (if > that was the question?) > > BR, > -R > > 2011/6/22 InKi Dae <daeinki@xxxxxxxxx>: >> It adds dri-devel@xxxxxxxxxxxxxxxxxxxxx to this mail thread. >> Thank you. >> >> 2011년 6월 22일 오후 3:04, daeinki <inki.dae@xxxxxxxxxxx>님의 말: >>> below is additional comments. >>> >>> daeinki 쓴 글: >>>> Hi all, >>>> >>>> I'm writing Samsung SoC based DRM framework and this one includes FIMD >>>> and HDMI driver as hardware dependent modules. and for now, encoder, >>>> connector, crtc and fb module has been materialized almost. but I'm >>>> contending with framebuffer setting issue(created fb_info should be >>>> registered to linux framebuffer through register_framebuffer() or not)as >>>> default framebuffer at booting time. >>>> >>>> at drm_fb_helper_single_fb_probe() of drm_fb_helper.c file, fb_helper's >>>> fb_probe callback is called and this one creates new framebuffer and >>>> returns a value more then 0 if true. internally, this process creates an >>>> fb_info object and drm_framebuffer and then drm_framebuffer would be >>>> added to mode_config.fb_list of the drm_device. >>>> >>> it's my mistake. return value is 0 if true, nonzero otherwise. >>> >>>> a value returned, new_fb is used to decide that it calls >>>> register_framebuffer() or drm_fb_helper_set_par(). at this point, I am >>>> confused it's a good way to call register_framebuffer() otherwise >>>> drm_fb_helper_set_par(). if register_framebuffer() is called then I >>>> guess drm_fb_helper_set_par() or drm_crtc_helper_set_config() should be >>>> called somewhere subsequently to apply this one to real hardware because >>>> previous process is just for maintaining data logically.(not set up data >>>> to h/w) >>>> >>>> it's a right way to call register_framebuffer() and then >>>> drm_fb_helper_set_par() or drm_crtc_helper_set_config()? otherwise just >>>> only drm_fb_helper_set_par() or drm_crtc_helper_set_config() ignoring >>>> register_framebuffer()? and what is the purpose of using >>>> register_framebuffer()? >>>> >>> I understood that if fb_probe() callback is fail then fb_info object is >>> registered to linux framebuffer through register_framebuffer() >>> otherwise(if true) hardware configuration would be completed by >>> drm_fb_helper_set_par() so the reason of using register_framebuffer() is >>> that the case of failing fb_probe() callback, it is for drawing on only >>> linux framebuffer. is it right? >>> >>>> In my case, first, register_framebuffer() is called and then if desired >>>> default crtc id is matched with drm_fb_helper->crtc_info[0 ~ n].crtc_id, >>>> it gets mode_set of drm_fb_helper->crtc_info[n] and then it calls >>>> drm_crtc_helper_set_config(mode_set). at this time, all the hardware >>>> configurations would be completed. >>>> >>>> thank you in advance. >>>> >>>> Best Regards >>>> Inki Dae. >>>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@xxxxxxxxxxxxxxxxxxxxx >> http://lists.freedesktop.org/mailman/listinfo/dri-devel >> > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
