In subject: "drm/virtio" to match previous history.
On Wed, Aug 30, 2023 at 07:15:31PM +0800, Sui Jingfeng wrote:
> From: Sui Jingfeng <[email protected]>
>
> Should be no functional change, just for cleanup purpose.
>
> Cc: David Airlie <[email protected]>
> Cc: Gerd Hoffmann <[email protected]>
> Cc: Gurchetan Singh <[email protected]>
> Cc: Chia-I Wu <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Signed-off-by: Sui Jingfeng <[email protected]>
> ---
> drivers/gpu/drm/virtio/virtgpu_drv.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
> index add075681e18..3a368304475a 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> @@ -51,7 +51,7 @@ static int virtio_gpu_pci_quirk(struct drm_device *dev)
> {
> struct pci_dev *pdev = to_pci_dev(dev->dev);
> const char *pname = dev_name(&pdev->dev);
> - bool vga = (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA;
> + bool vga = pci_is_vga(pdev);
This *is* a functional change: Previously "vga" was only true for
PCI_CLASS_DISPLAY_VGA (0x0300). Now it will be true for both
PCI_CLASS_DISPLAY_VGA (0x0300) and PCI_CLASS_DISPLAY_OTHER (0x0380).
Is that desirable? I can't tell. Maybe the GPU folks will chime in.
> int ret;
>
> DRM_INFO("pci: %s detected at %s\n",
> --
> 2.34.1
>
On Thu, Oct 05, 2023 at 04:57:14PM -0500, Bjorn Helgaas wrote:
> In subject: "drm/virtio" to match previous history.
>
> On Wed, Aug 30, 2023 at 07:15:31PM +0800, Sui Jingfeng wrote:
> > From: Sui Jingfeng <[email protected]>
> >
> > Should be no functional change, just for cleanup purpose.
> >
> > Cc: David Airlie <[email protected]>
> > Cc: Gerd Hoffmann <[email protected]>
> > Cc: Gurchetan Singh <[email protected]>
> > Cc: Chia-I Wu <[email protected]>
> > Cc: Daniel Vetter <[email protected]>
> > Signed-off-by: Sui Jingfeng <[email protected]>
> > ---
> > drivers/gpu/drm/virtio/virtgpu_drv.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
> > index add075681e18..3a368304475a 100644
> > --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> > +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> > @@ -51,7 +51,7 @@ static int virtio_gpu_pci_quirk(struct drm_device *dev)
> > {
> > struct pci_dev *pdev = to_pci_dev(dev->dev);
> > const char *pname = dev_name(&pdev->dev);
> > - bool vga = (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA;
> > + bool vga = pci_is_vga(pdev);
>
> This *is* a functional change: Previously "vga" was only true for
> PCI_CLASS_DISPLAY_VGA (0x0300). Now it will be true for both
> PCI_CLASS_DISPLAY_VGA (0x0300) and PCI_CLASS_DISPLAY_OTHER (0x0380).
Oops, sorry, my mistake here. I meant PCI_CLASS_NOT_DEFINED_VGA, not
PCI_CLASS_DISPLAY_OTHER. pci_is_vga() is true for either of:
PCI_CLASS_DISPLAY_VGA 0x0300
PCI_CLASS_NOT_DEFINED_VGA 0x0001
(PCI_CLASS_NOT_DEFINED_VGA is defined in the PCI Code and Assignment
spec r1.15, sec 1.1; PCI_CLASS_DISPLAY_VGA is sec 1.4.)
> Is that desirable? I can't tell. Maybe the GPU folks will chime in.
>
> > int ret;
> >
> > DRM_INFO("pci: %s detected at %s\n",
> > --
> > 2.34.1
> >
Hi,
On 2023/10/6 05:57, Bjorn Helgaas wrote:
> In subject: "drm/virtio" to match previous history.
>
> On Wed, Aug 30, 2023 at 07:15:31PM +0800, Sui Jingfeng wrote:
>> From: Sui Jingfeng <[email protected]>
>>
>> Should be no functional change, just for cleanup purpose.
>>
>> Cc: David Airlie <[email protected]>
>> Cc: Gerd Hoffmann <[email protected]>
>> Cc: Gurchetan Singh <[email protected]>
>> Cc: Chia-I Wu <[email protected]>
>> Cc: Daniel Vetter <[email protected]>
>> Signed-off-by: Sui Jingfeng <[email protected]>
>> ---
>> drivers/gpu/drm/virtio/virtgpu_drv.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
>> index add075681e18..3a368304475a 100644
>> --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
>> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
>> @@ -51,7 +51,7 @@ static int virtio_gpu_pci_quirk(struct drm_device *dev)
>> {
>> struct pci_dev *pdev = to_pci_dev(dev->dev);
>> const char *pname = dev_name(&pdev->dev);
>> - bool vga = (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA;
>> + bool vga = pci_is_vga(pdev);
> This *is* a functional change: Previously "vga" was only true for
> PCI_CLASS_DISPLAY_VGA (0x0300). Now it will be true for both
> PCI_CLASS_DISPLAY_VGA (0x0300) and PCI_CLASS_DISPLAY_OTHER (0x0380).
>
> Is that desirable? I can't tell. Maybe the GPU folks will chime in.
>
Yes, the vga variable still will be "true" for the PCI_CLASS_DISPLAY_VGA (0x0300) class code,
and this is the major case. But the devices with PCI_CLASS_NOT_DEFINED_VGA class code are quite
uncommon, and virtio gpu is virtual GPU driver, It is unlikely that the QEMU to emulate a
old device with PCI_CLASS_NOT_DEFINED_VGA class code. I means that there no reason to do so.
Am I correct? Is there anyone know more?
For virtio virtual GPU driver, I would like to drop this patch, if no one response.
We probably only need to consider PCI_CLASS_NOT_DEFINED_VGA case for the real (probably old) hardware device.
It do exists, as Maciej mention at [1].
[1] https://lkml.org/lkml/2023/6/18/315
>> int ret;
>>
>> DRM_INFO("pci: %s detected at %s\n",
>> --
>> 2.34.1
>>