Hi Am 05.07.23 um 11:34 schrieb Javier Martinez Canillas:
Thomas Zimmermann <tzimmermann@xxxxxxx> writes: [...]+ info->flags |= FBINFO_VIRTFB;I see that all fbdev drivers just do: info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB Guess you are doing in two assignments to be consistent with drm_fbdev_dma.c ? I was just curious about the rationale for setting the flags in two steps.The _DEFAULT flag is really just a zero. And the other flags describe different aspects of the framebuffer. I think it makes sense to set the flags together with the respective state. For example, _VIRTFB is set next to ->screen_buffer, because they belong together.Yes, that makes sense._VIRTFB is currently only used in defio code at https://elixir.bootlin.com/linux/latest/source/drivers/video/fbdev/core/fb_defio.c#L232 I think the fbdev I/O helpers should also test this flag after all drivers have been annotated correctly. For example, fb_io_read() would WARN_ONCE if the _VIRTFB flag has been set; and fb_sys_read() would warn if it hasn't been set. For the read helpers, it also makes sense to WARN_ONCE if the _READS_FAST flag has not been set.Agreed. Maybe you could add those warn (or at least info or debug?) even if not all drivers have been annotated correctly. That way people can be aware that is missing and fix if there are remaining drivers.
Yes, we could do that. I want to go through drivers first and fix the low-hanging fruits. Some of the old fbdev drivers use either DMA or I/O memory. They would only be fix-worthy if someone complains.
Best regards Thomas
Best regards Thomas
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)
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