[PATCH] mfd: intel-lpss: add Dell Latitude 7275 to the resource conflict quirk

[D. Manresa]

The Dell Latitude 7275 2-in-1 has the same BIOS bug as the Latitude 5285:
the ACPI GEXP device declares an OperationRegion (BAR0) on the GNVS
variable SB04 and the I2C4 controller (INT3446) builds its _CRS from that
same variable, so intel_lpss_acpi fails to bind the controller with
-EBUSY and the front camera sensor (OV5670, INT3479) is never registered
unless acpi_enforce_resources=lax is passed.

Add the machine to the DMI table so QUIRK_IGNORE_RESOURCE_CONFLICTS is
applied to INT3446 on it as well.

Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: D. Manresa <dmanresa@xxxxxxxxx>
---
Applies on top of "mfd: intel-lpss: add resource conflict quirk for Dell
Latitude 5285" from Thierry Chatard's v10 series [1]. Thierry, feel free
to fold this into v11 instead if you prefer.

The conflict was verified in the 7275 DSDT (BIOS 1.18.0): GEXP has
OperationRegion (BAR0, SystemMemory, SB04, 0x0208) and INT3446._CRS
returns LCRS (SMD4, SB04, SIR4). With acpi_enforce_resources=lax, which
has the same effect as the quirk, the controller binds and the camera
works with the board data from "platform/x86: int3472: Add TPS68470 board
data for Dell Latitude 7275" [2]. The distribution kernel here builds
intel-lpss-acpi in, so this exact patch has not been run yet.

[1] https://lore.kernel.org/linux-media/20260831160754.9857-2-tchatard@xxxxxxxxx/
[2] https://lore.kernel.org/platform-driver-x86/20260908161445.334910-1-dmanresa@xxxxxxxxx/

 drivers/mfd/intel-lpss-acpi.c | 6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/mfd/intel-lpss-acpi.c
+++ b/drivers/mfd/intel-lpss-acpi.c
@@ -191,6 +191,12 @@ static const struct dmi_system_id intel_lpss_quirk_dmi[] = {
 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5285"),
 		},
 	},
+	{
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 7275"),
+		},
+	},
 	{ }
 };