[PATCH 01/11] drm/ast: Use drm_aperture_remove_conflicting_pci_framebuffers

Jammy Huang jammy_huang at aspeedtech.com
Tue Apr 18 00:53:48 UTC 2023


Hi Thomas,

The Intel(x86) CPUs have a separate address space for "IO", but the ARM 
architecture only has "memory", so all IO devices are accessed as if 
they were memory. Which means ARM does not support isolated IO. Here is 
a related discussion on ARM's forum.

https://community.arm.com/support-forums/f/architectures-and-processors-forum/52046/how-to-read-write-an-i-o-port-in-aarch64

Thus, we adapt MMIO only after this patch.


On 2023/4/4 下午 10:45, Thomas Zimmermann wrote:
> Hi,
>
> FYI I have merged patches 1, 6 and 7 of this patchset. They look fine 
> and are worthwhile fixes on their own.
>
> Best regards
> Thomas
>
> Am 11.01.23 um 16:41 schrieb Daniel Vetter:
>> It's just open coded and matches.
>>
>> Note that Thomas said that his version apparently failed for some
>> reason, but hey maybe we should try again.
>>
>> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>> Cc: Dave Airlie <airlied at redhat.com>
>> Cc: Thomas Zimmermann <tzimmermann at suse.de>
>> Cc: Javier Martinez Canillas <javierm at redhat.com>
>> Cc: Helge Deller <deller at gmx.de>
>> Cc: linux-fbdev at vger.kernel.org
>> ---
>>   drivers/gpu/drm/ast/ast_drv.c | 16 +---------------
>>   1 file changed, 1 insertion(+), 15 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ast/ast_drv.c 
>> b/drivers/gpu/drm/ast/ast_drv.c
>> index 420fc75c240e..3ac24a780f50 100644
>> --- a/drivers/gpu/drm/ast/ast_drv.c
>> +++ b/drivers/gpu/drm/ast/ast_drv.c
>> @@ -90,27 +90,13 @@ static const struct pci_device_id ast_pciidlist[] 
>> = {
>>     MODULE_DEVICE_TABLE(pci, ast_pciidlist);
>>   -static int ast_remove_conflicting_framebuffers(struct pci_dev *pdev)
>> -{
>> -    bool primary = false;
>> -    resource_size_t base, size;
>> -
>> -    base = pci_resource_start(pdev, 0);
>> -    size = pci_resource_len(pdev, 0);
>> -#ifdef CONFIG_X86
>> -    primary = pdev->resource[PCI_ROM_RESOURCE].flags & 
>> IORESOURCE_ROM_SHADOW;
>> -#endif
>> -
>> -    return drm_aperture_remove_conflicting_framebuffers(base, size, 
>> primary, &ast_driver);
>> -}
>> -
>>   static int ast_pci_probe(struct pci_dev *pdev, const struct 
>> pci_device_id *ent)
>>   {
>>       struct ast_private *ast;
>>       struct drm_device *dev;
>>       int ret;
>>   -    ret = ast_remove_conflicting_framebuffers(pdev);
>> +    ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, 
>> &ast_driver);
>>       if (ret)
>>           return ret;
>
-- 
Best Regards
Jammy



More information about the dri-devel mailing list