ASoC: amd: ps: disable MSI on resume in ACP PCI driver

BIOS/firmware may re-enable MSI in PCI config space during system
level resume even though this driver only uses legacy INTx interrupts.
If MSI is left enabled with stale address/data registers, the device
will write interrupts to a bogus address causing IOMMU IO_PAGE_FAULT
and interrupt delivery failure.

Clear the MSI Enable bit before reinitializing the ACP hardware on
system level resume.

Fixes: 491628388005 ("ASoC: amd: ps: add callback functions for acp pci driver pm ops")
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Link: https://patch.msgid.link/20260707060130.2514138-2-Vijendar.Mukunda@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/amd/ps/pci-ps.c b/sound/soc/amd/ps/pci-ps.c
index 4ecda224157b5f58ab2a4474e6ad1fe980a000e8..635832da45f986f114317b15dbc0712dd5b578e0 100644 (file)
--- a/sound/soc/amd/ps/pci-ps.c
+++ b/sound/soc/amd/ps/pci-ps.c
@@ -693,8 +693,37 @@ static int snd_acp_runtime_resume(struct device *dev)
        return acp_hw_runtime_resume(dev);
 }
 
+static void acp_disable_msi_on_resume(struct pci_dev *pdev)
+{
+       u16 control;
+
+       if (!pdev->msi_cap)
+               return;
+
+       pci_read_config_word(pdev, pdev->msi_cap + PCI_MSI_FLAGS, &control);
+       if (control & PCI_MSI_FLAGS_ENABLE) {
+               dev_warn(&pdev->dev,
+                        "ACP: MSI unexpectedly enabled after resume (flags=0x%04x), disabling\n",
+                        control);
+               control &= ~PCI_MSI_FLAGS_ENABLE;
+               pci_write_config_word(pdev, pdev->msi_cap + PCI_MSI_FLAGS, control);
+       }
+}
+
 static int snd_acp_resume(struct device *dev)
 {
+       struct pci_dev *pdev = to_pci_dev(dev);
+
+       /*
+        * BIOS/firmware may re-enable MSI in PCI config space during
+        * system resume even though this driver only uses legacy INTx
+        * interrupts. If MSI is left enabled with stale address/data
+        * registers, the device will write interrupts to a bogus address
+        * causing IOMMU IO_PAGE_FAULT and interrupt delivery failure.
+        * Explicitly clear the MSI Enable bit before reinitializing
+        * the ACP hardware.
+        */
+       acp_disable_msi_on_resume(pdev);
        return acp_hw_resume(dev);
 }