Subject: Re: linux-next: Tree for Apr 9 (x86 boot problem)

From: Mike Rapoport <[email-masked]>
Date: Tue, 13 Apr 2021 09:06:20 +0300

Hi Randy,

On Mon, Apr 12, 2021 at 01:53:34PM -0700, Randy Dunlap wrote:
> On 4/12/21 10:01 AM, Mike Rapoport wrote:
> > On Mon, Apr 12, 2021 at 08:49:49AM -0700, Randy Dunlap wrote:
> >  
> > I thought about adding some prints to see what's causing the hang, the
> > reservations or their absence. Can you replace the debug patch with this
> > one:
> > 
> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> > index 776fc9b3fafe..a10ac252dbcc 100644
> > --- a/arch/x86/kernel/setup.c
> > +++ b/arch/x86/kernel/setup.c
> > @@ -600,10 +600,13 @@ static bool __init snb_gfx_workaround_needed(void)
> >  		return false;
> >  
> >  	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
> > +	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
> > +
> > +	pr_info("%s: vendor: %x, device: %x\n", __func__, vendor, device);
> 
> s/device)/devid)/
 
Oh, sorry.

> > +
> >  	if (vendor != 0x8086)
> >  		return false;
> >  
> > -	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
> >  	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
> >  		if (devid == snb_ids[i])
> >  			return true;
> 
> That prints:
> 
> [    0.000000] snb_gfx_workaround_needed: vendor: 8086, device: 126
> [    0.000000] early_reserve_memory: snb_gfx: 1
> ...
> [    0.014061] snb_gfx_workaround_needed: vendor: 8086, device: 126
> [    0.014064] reserving inaccessible SNB gfx pages
> 
> 
> The full boot log is attached.
 
Can you please send the log with memblock=debug added to the kernel command
line?

Probably should have started from this...

-- 
Sincerely yours,
Mike.