Messages in this thread Patch in this message | | | From | "Luis R. Rodriguez" <> | Subject | [PATCH v3 16/17] video: fbdev: atmel_lcdfb: use ioremap_wc() for framebuffer | Date | Tue, 21 Apr 2015 13:16:37 -0700 |
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From: "Luis R. Rodriguez" <mcgrof@suse.com>
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 de33c442e 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: Luis R. Rodriguez <mcgrof@suse.com> --- drivers/video/fbdev/atmel_lcdfb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/video/fbdev/atmel_lcdfb.c b/drivers/video/fbdev/atmel_lcdfb.c index 94a8d04..abadc49 100644 --- a/drivers/video/fbdev/atmel_lcdfb.c +++ b/drivers/video/fbdev/atmel_lcdfb.c @@ -1266,7 +1266,8 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev) goto stop_clk; } - info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len); + info->screen_base = ioremap_wc(info->fix.smem_start, + info->fix.smem_len); if (!info->screen_base) { ret = -ENOMEM; goto release_intmem; -- 2.3.2.209.gd67f9d5.dirty
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