Hello Tejun, [Tejun: sorry for duplicate, did hit "reply" instead of "reply to all"] On Mon, 13 Aug 2012 16:27:08 Tejun Heo <tj@xxxxxxxxxx> wrote: > On Thu, Aug 09, 2012 at 08:09:47PM +0200, Bruno Prémont wrote: > > As you are working on workqueues and related code, could you have a look > > at my usage of them in combination with db_defio? > > > > The delayed memory corruptions or system reboots after unbinding/unplugging > > the PicoLCD seem very much related to workqueue used to handle the deferred > > IO to framebuffer. > > > > I think things don't get cleaned-up as they should though I'm not sure > > where the trouble lies. > > > > For ease of reading, I'm inlineing below the framebuffer related code of > > PicoLCD (for complete driver after this patch series apply the whole series > > on top of 3.5 https://lkml.org/lkml/2012/7/30/375 ) > ... > > void picolcd_exit_framebuffer(struct picolcd_data *data) > > { > > struct fb_info *info = data->fb_info; > > u8 *fb_vbitmap = data->fb_vbitmap; > > > > if (!info) > > return; > > > > device_remove_file(&data->hdev->dev, &dev_attr_fb_update_rate); > > info->par = NULL; > > unregister_framebuffer(info); > > data->fb_vbitmap = NULL; > > data->fb_bitmap = NULL; > > data->fb_bpp = 0; > > data->fb_info = NULL; > > kfree(fb_vbitmap); > > } > > I'm kinda shooting in the dark but who flushes / cancels > fb_info->deferred_work? fb_deferred_io_cleanup() does so and is called by destroy fbops (when last reference to fb_info is returned): static void picolcd_fb_destroy(struct fb_info *info) { /* make sure no work is deferred */ fb_deferred_io_cleanup(info); vfree((u8 *)info->fix.smem_start); framebuffer_release(info); printk(KERN_DEBUG "picolcd_fb_destroy(%p)\n", info); } ===== drivers/video/fb_defio.c ===== void fb_deferred_io_cleanup(struct fb_info *info) { struct fb_deferred_io *fbdefio = info->fbdefio; struct page *page; int i; BUG_ON(!fbdefio); cancel_delayed_work_sync(&info->deferred_work); /* clear out the mapping that we setup */ for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) { page = fb_deferred_io_page(info, i); page->mapping = NULL; } info->fbops->fb_mmap = NULL; mutex_destroy(&fbdefio->lock); } Thanks, Bruno -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
