931e3f3a0e
Add a mutex lock to protect concurrent access to I/O registers against each other. This happens between invocation of commit- tail functions and get-mode operations. Both with use the CRTC index registers MGA1064_GEN_IO_DATA and MGA1064_GEN_IO_CTL. Concurrent access can lead to failed mode-setting operations. v2: * fix typo in commit description (Jocelyn) * add comment to explain rmmio_lock Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20220502142514.2174-4-tzimmermann@suse.de