Hi Jaya, On Mon, 10 May 2010 08:00:51 Jaya Kumar wrote: > On Mon, May 10, 2010 at 12:49 AM, Bruno Prémont > <bonbons@xxxxxxxxxxxxxxxxx> wrote: > > > > Fix crash if we are the first framebuffer loaded as in that case > > fbcon wants to flush framebuffer at the end of fb registration, > > before we have setup fb_defio. > > Bruno, > > Please help me understand, how does this scenario occur? I'm > interpreting what you've written above to mean that fbcon is accessing > the framebuffer before you've called defio_init()? Is that correct? That was the original state as I called defio_init after register_framebuffer() and defio_cleanup() before unregister_framebuffer(), the opposite to the typical sequence you detail below. Fixed by the patch. My deadlock issue, after applying the patch, is during set_par() when I replace the framebuffer and wish defio to start using the new page(s) instead of the old one(s). I want to make sure that I won't be accessing the old framebuffer after freeing it and also that defio monitors the new framebuffer. For that reason I defio_cleanup(), replace framebuffer, defio_init(). All of this happens while do_fb_ioctl() holds lock on fb_info and console_sem. Thanks, Bruno > The typical defio use sequence is: defio_init(), > register_framebuffer() and the typical remove sequence is in the > reverse order unregister_framebuffer(), defio_cleanup(). So, I don't > see how fbcon is accessing the framebuffer either before > register_framebuffer() completes (at which point defio init is already > done) or after unregister_framebuffer() completes. > > 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
