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From: "Tian, Kevin" <kevin.tian@intel.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>, LKML
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Subject: RE: [PATCH v2 11/13] iommu/vt-d: Make posted MSI an opt-in cmdline
 option
Thread-Topic: [PATCH v2 11/13] iommu/vt-d: Make posted MSI an opt-in cmdline
 option
Thread-Index: AQHah6hi0qfZeBkquE2g8LsVrlLDi7FkZ5DQ
Date: Fri, 12 Apr 2024 09:31:32 +0000
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References: <20240405223110.1609888-1-jacob.jun.pan@linux.intel.com>
 <20240405223110.1609888-12-jacob.jun.pan@linux.intel.com>
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> From: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Sent: Saturday, April 6, 2024 6:31 AM
>=20
> +#ifdef CONFIG_X86_POSTED_MSI
> +		else if (!strncmp(str, "posted_msi", 10)) {
> +			if (disable_irq_post || disable_irq_remap)
> +				pr_warn("Posted MSI not enabled due to
> conflicting options!");
> +			else
> +				enable_posted_msi =3D 1;
> +		}
> +#endif

the check of disable_irq_remap is unnecessary. It's unlikely to have
a configuration with disable_irq_post=3D0 while disable_irq_remap=3D1
given the latter has bigger scope.

but thinking more do we really need a check here? there is no order
guarantee that "posted_msi" is parsed after the parameters deciding
the value of two disable variables.

it probably makes more sense to just set enable_posted_msi here
and then do all required checks when picking up the irqchip in
intel_irq_remapping_alloc().