Re: [PATCH v5 1/5] x86/quirks: Fix stolen detection with integrated + discrete GPU

From: Borislav Petkov <bp@alien8.de>
To: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: x86@kernel.org, "Dave Hansen" <dave.hansen@linux.intel.com>,
	"Ingo Molnar" <mingo@redhat.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	linux-pci@vger.kernel.org, intel-gfx@lists.freedesktop.org,
	"Ville Syrjälä" <ville.syrjala@linux.intel.com>,
	"Matt Roper" <matthew.d.roper@intel.com>,
	"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH v5 1/5] x86/quirks: Fix stolen detection with integrated + discrete GPU
Date: Tue, 18 Jan 2022 20:14:24 +0100	[thread overview]
Message-ID: <YecRkGidIS10N0md@zn.tnic> (raw)
In-Reply-To: <20220118190558.2ququ4vdfjuahicm@ldmartin-desk2>

On Tue, Jan 18, 2022 at 11:05:58AM -0800, Lucas De Marchi wrote:
> I think to make it similar how the PCI fixups work. Anyway, do you
> prefer that I change the QFLAG_APPLY_ONCE as above (including
> nvidia_bugs() and ati_bugs()) or a very minimal fix like below and
> nothing else?
> 
> ------8<------
> diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
> index 391a4e2b8604..7b2a3230c42a 100644
> --- a/arch/x86/kernel/early-quirks.c
> +++ b/arch/x86/kernel/early-quirks.c
> @@ -591,6 +591,13 @@ static void __init intel_graphics_quirks(int num, int slot, int func)
>  	u16 device;
>  	int i;
> +	/*
> +	 * Already reserved for integrated graphics, nothing to do for other
> +	 * (discrete) cards.
> +	 */
> +	if (resource_size(&intel_graphics_stolen_res))
> +		return;
> +
>  	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
>  	for (i = 0; i < ARRAY_SIZE(intel_early_ids); i++) {
> @@ -703,7 +710,7 @@ static struct chipset early_qrk[] __initdata = {
>  	{ PCI_VENDOR_ID_INTEL, 0x3406, PCI_CLASS_BRIDGE_HOST,
>  	  PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check },
>  	{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID, PCI_CLASS_DISPLAY_VGA, PCI_ANY_ID,
> -	  QFLAG_APPLY_ONCE, intel_graphics_quirks },
> +	  0, intel_graphics_quirks },
>  	/*
>  	 * HPET on the current version of the Baytrail platform has accuracy
>  	 * problems: it will halt in deep idle state - so we disable it.
> ------8<------

This looks even cleaner to me but that's Bjorn's call in the end.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette