Hi
On Wed, Dec 18, 2013 at 4:38 PM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote:
> Hi
>
> On Sat, Nov 30, 2013 at 2:52 PM, Bruno Prémont
> <bonbons@xxxxxxxxxxxxxxxxx> wrote:
>> With commit b4aa0163056b6c70029b6e8619ce07c274351f42 Matthew Garret
>> introduced a efifb vga_default_device() so that EFI systems that do not
>> load shadow VBIOS or setup VGA get proper value for boot_vga PCI sysfs
>> attribute on the corresponding PCI device.
>>
>> Xorg is refusing to detect devices when boot_vga=0 which is the case
>> on some EFI system (e.g. MacBookAir2,1). Xorg detects the GPU and finds
>> the dri device but then bails out with "no devices detected".
>>
>> With introduction of sysfb/simplefb/simpledrm efifb is getting obsolete
>> while having native drivers for the GPU also makes selecting sysfb/efifb
>> optional.
>>
>> Remove the efifb implementation of vga_default_device() and initialize
>> vgaarb's vga_default_device() with the PCI GPU that matches boot
>> screen_info in x86's pci_fixup_video().
>>
>> Notes:
>> - Other architectures with PCI GPU might need a similar fixup.
>> - If CONFIG_VGA_ARB is unset vga_default_device() is only available
>> as a stub that returns NULL, making this adjustment insufficient.
>> Unsetting CONFIG_VGA_ARB requires CONFIG_EXPERT=y though.
>>
>> Signed-off-by: Bruno Prémont <bonbons@xxxxxxxxxxxxxxxxx>
>> ---
>> arch/x86/include/asm/vga.h | 6 ------
>> arch/x86/pci/fixup.c | 21 +++++++++++++++++++++
>> drivers/video/efifb.c | 38 --------------------------------------
>> 3 files changed, 21 insertions(+), 44 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/vga.h b/arch/x86/include/asm/vga.h
>> index 44282fb..c4b9dc2 100644
>> --- a/arch/x86/include/asm/vga.h
>> +++ b/arch/x86/include/asm/vga.h
>> @@ -17,10 +17,4 @@
>> #define vga_readb(x) (*(x))
>> #define vga_writeb(x, y) (*(y) = (x))
>>
>> -#ifdef CONFIG_FB_EFI
>> -#define __ARCH_HAS_VGA_DEFAULT_DEVICE
>> -extern struct pci_dev *vga_default_device(void);
>> -extern void vga_set_default_device(struct pci_dev *pdev);
>> -#endif
>> -
>> #endif /* _ASM_X86_VGA_H */
>> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
>> index f5809fa..440343e 100644
>> --- a/arch/x86/pci/fixup.c
>> +++ b/arch/x86/pci/fixup.c
>> @@ -6,6 +6,7 @@
>> #include <linux/dmi.h>
>> #include <linux/pci.h>
>> #include <linux/init.h>
>> +#include <linux/screen_info.h>
>> #include <linux/vgaarb.h>
>> #include <asm/pci_x86.h>
>>
>> @@ -323,6 +324,26 @@ static void pci_fixup_video(struct pci_dev *pdev)
>> struct pci_bus *bus;
>> u16 config;
>>
>> + if (!vga_default_device()) {
>> + resource_size_t start, end;
>> + int i;
>> +
>> + for (i=0; i < DEVICE_COUNT_RESOURCE; i++) {
>> + if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM))
>> + continue;
>> +
>> + start = pci_resource_start(pdev, i);
>> + end = pci_resource_end(pdev, i);
>> +
>> + if (!start || !end)
>> + continue;
>> +
>> + if (screen_info.lfb_base >= start &&
>> + (screen_info.lfb_base + screen_info.lfb_size) < end)
>
> pci_resource_end() returns the address of the end, not the length, so
> we have a double off-by-one error here, don't we?
> Shouldn't this be:
> (screen_info.lfb_base +
> screen_info.lfb_size) <= end + 1)
>
> Oh, and lfb_size is in multiples of 0xffff, so it actually needs to be:
> (screen_info.lfb_base +
> ((u64)screen_info.lfb_size << 16)) <= end + 1)
Oh, just remembered that this is only done for VESA, not EFI.
Awesome.. so the "<< 16" shift is not needed.
David
> I know, it's copy/paste, but we could still fix it here.
>
>> + vga_set_default_device(pdev);
>> + }
>> + }
>> +
>> /* Is VGA routed to us? */
>> bus = pdev->bus;
>> while (bus) {
>> diff --git a/drivers/video/efifb.c b/drivers/video/efifb.c
>> index 7f9ff75..fb3fb50 100644
>> --- a/drivers/video/efifb.c
>> +++ b/drivers/video/efifb.c
>> @@ -19,8 +19,6 @@
>>
>> static bool request_mem_succeeded = false;
>>
>> -static struct pci_dev *default_vga;
>> -
>> static struct fb_var_screeninfo efifb_defined = {
>> .activate = FB_ACTIVATE_NOW,
>> .height = -1,
>> @@ -85,18 +83,6 @@ static struct fb_ops efifb_ops = {
>> .fb_imageblit = cfb_imageblit,
>> };
>>
>> -struct pci_dev *vga_default_device(void)
>> -{
>> - return default_vga;
>> -}
>> -
>> -EXPORT_SYMBOL_GPL(vga_default_device);
>> -
>> -void vga_set_default_device(struct pci_dev *pdev)
>> -{
>> - default_vga = pdev;
>> -}
>> -
>> static int efifb_setup(char *options)
>> {
>> char *this_opt;
>> @@ -127,30 +113,6 @@ static int efifb_setup(char *options)
>> }
>> }
>
> I wonder whether we should move the efifb_setup() argument parsing to
> x86/kernel/sysfb.c now. Because currently we break simplefb-conversion
> and the vga_boot flag if we keep it here.
>
> Otherwise, the patch looks good to me.
> Thanks
> David
>
>>
>> - for_each_pci_dev(dev) {
>> - int i;
>> -
>> - if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
>> - continue;
>> -
>> - for (i=0; i < DEVICE_COUNT_RESOURCE; i++) {
>> - resource_size_t start, end;
>> -
>> - if (!(pci_resource_flags(dev, i) & IORESOURCE_MEM))
>> - continue;
>> -
>> - start = pci_resource_start(dev, i);
>> - end = pci_resource_end(dev, i);
>> -
>> - if (!start || !end)
>> - continue;
>> -
>> - if (screen_info.lfb_base >= start &&
>> - (screen_info.lfb_base + screen_info.lfb_size) < end)
>> - default_vga = dev;
>> - }
>> - }
>> -
>> return 0;
>> }
>>
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/dri-devel
