<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - DRM bootup error on VX900 platform" href="https://bugs.freedesktop.org/show_bug.cgi?id=94473#c11">Comment # 11</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - DRM bootup error on VX900 platform" href="https://bugs.freedesktop.org/show_bug.cgi?id=94473">bug 94473</a> from <a class="email" href="mailto:huangran@iscas.ac.cn" title="HuangRan <huangran@iscas.ac.cn>"> HuangRan</a> <pre>With my initial analysis, via_driver_load() is called by DRM .load function and via_driver_load() will do GPU initialization work including VRAM/TTM, mmmio, HW engine,vblank and so on. So the function via_detect_agp() is called. And an DRM function drm_agp_acquire() then is called by via.ko which return negative value causing this error happen. And drm_agp_acquire() is defined in DRM file drm_agpsupport.c which we need debug to see why negative value(-ENODEV/-EBUSY) is returned. By contrast, The UMS driver VIADRIAgpInit() will trigger a AGP function call drmAgpAcquire() which will call libDRM function with DRM_IOCTL_AGP_ACQUIRE, then into DRM kernel function drm_agp_acquire_ioctl(), and finally call the same function drm_agp_acquire() which does not cause any error! So I believe this is something missing to do in current KMS driver I need follow debubgging to get the root cause. Thanks, Frank</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>