This is a note to let you know that I've just added the patch titled
fbdev: atyfb: only use ioremap_uc() on i386 and ia64
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fbdev-atyfb-only-use-ioremap_uc-on-i386-and-ia64.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4bf0e3e43d932cebdeeaf74370ba6ec3e9e17884
Author: Arnd Bergmann <arnd@xxxxxxxx>
Date: Thu Sep 21 19:04:21 2023 +0800
fbdev: atyfb: only use ioremap_uc() on i386 and ia64
[ Upstream commit c1a8d1d0edb71dec15c9649cb56866c71c1ecd9e ]
ioremap_uc() is only meaningful on old x86-32 systems with the PAT
extension, and on ia64 with its slightly unconventional ioremap()
behavior, everywhere else this is the same as ioremap() anyway.
Change the only driver that still references ioremap_uc() to only do so
on x86-32/ia64 in order to allow removing that interface at some
point in the future for the other architectures.
On some architectures, ioremap_uc() just returns NULL, changing
the driver to call ioremap() means that they now have a chance
of working correctly.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: linux-fbdev@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
index 1aef3d6ebd880..246bf67b32ea0 100644
--- a/drivers/video/fbdev/aty/atyfb_base.c
+++ b/drivers/video/fbdev/aty/atyfb_base.c
@@ -3447,11 +3447,15 @@ static int atyfb_setup_generic(struct pci_dev *pdev, struct fb_info *info,
}
info->fix.mmio_start = raddr;
+#if defined(__i386__) || defined(__ia64__)
/*
* By using strong UC we force the MTRR to never have an
* effect on the MMIO region on both non-PAT and PAT systems.
*/
par->ati_regbase = ioremap_uc(info->fix.mmio_start, 0x1000);
+#else
+ par->ati_regbase = ioremap(info->fix.mmio_start, 0x1000);
+#endif
if (par->ati_regbase == NULL)
return -ENOMEM;
