Re: [PATCH] drm/r128: fix build for UML

[Johannes Berg]

On Wed, 2021-09-01 at 19:17 -0700, Randy Dunlap wrote:
> Fix a build error on CONFIG_UML, which does not support (provide)
> wbinvd(). UML can use the generic mb() instead.
> 
> ../drivers/gpu/drm/r128/ati_pcigart.c: In function ‘drm_ati_pcigart_init’:
> ../drivers/gpu/drm/r128/ati_pcigart.c:218:2: error: implicit declaration of 
> function ‘wbinvd’ [-Werror=implicit-function-declaration]
>   wbinvd();
>   ^~
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") # pre-git

Arguably, that could be

Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver")

because prior to that, Kconfig options depending on PCI couldn't be
selected on ARCH=um.

johannes

[PATCH] drm/r128: fix build for UML

[Randy Dunlap]

Fix a build error on CONFIG_UML, which does not support (provide)
wbinvd(). UML can use the generic mb() instead.

../drivers/gpu/drm/r128/ati_pcigart.c: In function ‘drm_ati_pcigart_init’:
../drivers/gpu/drm/r128/ati_pcigart.c:218:2: error: implicit declaration of 
function ‘wbinvd’ [-Werror=implicit-function-declaration]
  wbinvd();
  ^~

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") # pre-git
Signed-off-by: Randy Dunlap 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: dri-devel@lists.freedesktop.org
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: linux...@lists.infradead.org
---
 drivers/gpu/drm/r128/ati_pcigart.c |2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20210901.orig/drivers/gpu/drm/r128/ati_pcigart.c
+++ linux-next-20210901/drivers/gpu/drm/r128/ati_pcigart.c
@@ -214,7 +214,7 @@ int drm_ati_pcigart_init(struct drm_devi
}
ret = 0;
 
-#if defined(__i386__) || defined(__x86_64__)
+#if (defined(__i386__) || defined(__x86_64__)) && !defined(CONFIG_UML)
wbinvd();
 #else
mb();