From 2d8112523aa04bca3f4d56d6ba1660082bf279b5 Mon Sep 17 00:00:00 2001 From: Stefan Reinauer Date: Mon, 20 May 2013 15:24:13 -0700 Subject: exynos5420: Clear the framebuffer before making it uncacheable If we clear the framebuffer and then flush it back to memory using cache operations, the writes are going to be full cachelines at a time. If we make it uncacheable first, the writes will be serialized writes of whatever sized chunks memset uses, probably 4 bytes or less. Change-Id: I960f87a370e97f9e91236ad796d931573bb3dbb8 Signed-off-by: Stefan Reinauer Signed-off-by: Gabe Black Reviewed-on: http://review.coreboot.org/3668 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/cpu/samsung/exynos5420/cpu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/cpu') diff --git a/src/cpu/samsung/exynos5420/cpu.c b/src/cpu/samsung/exynos5420/cpu.c index 1d511743b2..6e360bf350 100644 --- a/src/cpu/samsung/exynos5420/cpu.c +++ b/src/cpu/samsung/exynos5420/cpu.c @@ -97,6 +97,8 @@ static void exynos_displayport_init(device_t dev) lcdbase = (uintptr_t)cbmem_add(CBMEM_ID_CONSOLE, fb_size); printk(BIOS_SPEW, "LCD framebuffer base is %p\n", (void *)(lcdbase)); + memset((void *)lcdbase, 0, fb_size); /* clear the framebuffer */ + /* * We need to clean and invalidate the framebuffer region and disable * caching as well. We assume that our dcache <--> memory address @@ -114,7 +116,6 @@ static void exynos_displayport_init(device_t dev) mmio_resource(dev, 1, lcdbase/KiB, (fb_size + KiB - 1)/KiB); printk(BIOS_DEBUG, "Initializing Exynos VGA, base %p\n", (void *)lcdbase); - memset((void *)lcdbase, 0, fb_size); /* clear the framebuffer */ ret = lcd_ctrl_init(fb_size, &panel, (void *)lcdbase); } -- cgit v1.2.3