• Luis R. Rodriguez's avatar
    video: fbdev: atmel_lcdfb: use ioremap_wc() for framebuffer · 1e43a203
    Luis R. Rodriguez authored
    The driver doesn't use mtrr_add() or arch_phys_wc_add() but
    since we know the framebuffer is isolated already on an
    ioremap() we can take advantage of write combining for
    performance where possible.
    
    In this case there are a few motivations for this:
    
    a) Take advantage of PAT when available
    
    b) Help with the goal of eventually using _PAGE_CACHE_UC over
       _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
       de33c442 titled "x86 PAT: fix performance drop for glx,
       use UC minus for ioremap(), ioremap_nocache() and
       pci_mmap_page_range()")
    
    Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
    Cc: Suresh Siddha <sbsiddha@gmail.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Dave Airlie <airlied@redhat.com>
    Cc: Antonino Daplas <adaplas@gmail.com>
    Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
    Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
    Cc: linux-fbdev@vger.kernel.org
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: default avatarLuis R. Rodriguez <mcgrof@suse.com>
    Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
    Reviewed-by: default avatarDave Airlie <airlied@redhat.com>
    Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
    1e43a203
atmel_lcdfb.c 40.1 KB