Re: [Intel-gfx] [PATCH v4] x86/quirks: Replace QFLAG_APPLY_ONCE with static locals

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jan 12, 2022 at 03:30:43PM -0800, Lucas De Marchi wrote:
> The flags are only used to mark a quirk to be called once and nothing
> else. Also, that logic may not be appropriate if the quirk wants to
> do additional filtering and set quirk as applied by itself.
> 
> So replace the uses of QFLAG_APPLY_ONCE with static local variables in
> the few quirks that use this logic and remove all the flags logic.
> 
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>

Only occurred to me now, but another, less intrusive approach would be
to just remove QFLAG_APPLY_ONCE from intel_graphics_quirks() and do
its bookkeeping internally, e.g.,

diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index 391a4e2b8604..7b655004e5fd 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -587,10 +587,14 @@ intel_graphics_stolen(int num, int slot, int func,
 
 static void __init intel_graphics_quirks(int num, int slot, int func)
 {
+	static bool stolen __initdata = false;
 	const struct intel_early_ops *early_ops;
 	u16 device;
 	int i;
 
+	if (stolen)
+		return;
+
 	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
 
 	for (i = 0; i < ARRAY_SIZE(intel_early_ids); i++) {
@@ -602,6 +606,7 @@ static void __init intel_graphics_quirks(int num, int slot, int func)
 		early_ops = (typeof(early_ops))driver_data;
 
 		intel_graphics_stolen(num, slot, func, early_ops);
+		stolen = true;
 
 		return;
 	}
@@ -703,7 +708,7 @@ 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.