2023-09-21 20:36:05

by Baoquan He

[permalink] [raw]
Subject: [PATCH v5 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64

From: Arnd Bergmann <[email protected]>

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 <[email protected]>
Signed-off-by: Baoquan He <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/video/fbdev/aty/atyfb_base.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
index 5c87817a4f4c..3dcf83f5e7b4 100644
--- a/drivers/video/fbdev/aty/atyfb_base.c
+++ b/drivers/video/fbdev/aty/atyfb_base.c
@@ -3440,11 +3440,15 @@ 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;

--
2.41.0


2023-09-24 02:36:33

by Helge Deller

[permalink] [raw]
Subject: Re: [PATCH v5 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64

On 9/21/23 13:04, Baoquan He wrote:
> From: Arnd Bergmann <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Baoquan He <[email protected]>
> Reviewed-by: Luis Chamberlain <[email protected]>
> Cc: Helge Deller <[email protected]>
> Cc: Thomas Zimmermann <[email protected]>
> Cc: Christophe Leroy <[email protected]>
> Cc: [email protected]
> Cc: [email protected]

applied to fbdev git tree.

Thanks!
Helge


> ---
> drivers/video/fbdev/aty/atyfb_base.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
> index 5c87817a4f4c..3dcf83f5e7b4 100644
> --- a/drivers/video/fbdev/aty/atyfb_base.c
> +++ b/drivers/video/fbdev/aty/atyfb_base.c
> @@ -3440,11 +3440,15 @@ 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;
>