[PATCH] platform/x86/intel/vsec: reset state before re-enumerating

[Guangshuo Li]

The change referenced by the Fixes tag split the VSEC enumeration logic
out of intel_vsec_pci_probe() and made PCIe error recovery call
intel_vsec_pci_init() directly. This avoids another pcim_enable_device()
devm action and another devm allocation during slot reset, but it also
means that error recovery reuses the priv structure allocated by probe.

On the initial probe, priv is zeroed by devm_kzalloc(), so state[],
suppliers[] and found_caps start from their initial values. During slot
reset, the existing aux devices are removed before re-enumerating, but
the reused priv still records the old devices as registered and the old
capabilities as found.

The next intel_vsec_pci_init() call can therefore short-circuit in
intel_vsec_register_device() with -EEXIST, or stop early because
found_caps already matches info->caps. The aux devices removed during
slot reset are then not recreated, leaving VSEC functionality missing
after PCIe error recovery.

Reset the VSEC registration state after removing the old aux devices and
before re-enumerating them.

Fixes: 348ccc754d89 ("platform/x86/intel/vsec: Fix enable_cnt imbalance on PCIe error recovery")
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/platform/x86/intel/vsec.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
index 3ae4557b32b4..52ac4b4460a2 100644
--- a/drivers/platform/x86/intel/vsec.c
+++ b/drivers/platform/x86/intel/vsec.c
@@ -51,6 +51,13 @@ struct vsec_priv {
 	unsigned long found_caps;
 };
 
+static void intel_vsec_reset_state(struct vsec_priv *priv)
+{
+	memset(priv->suppliers, 0, sizeof(priv->suppliers));
+	memset(priv->state, 0, sizeof(priv->state));
+	priv->found_caps = 0;
+}
+
 static const char *intel_vsec_name(enum intel_vsec_id id)
 {
 	switch (id) {
@@ -850,6 +857,7 @@ static pci_ers_result_t intel_vsec_pci_slot_reset(struct pci_dev *pdev)
 {
 	struct intel_vsec_device *intel_vsec_dev;
 	pci_ers_result_t status = PCI_ERS_RESULT_DISCONNECT;
+	struct vsec_priv *priv = pci_get_drvdata(pdev);
 	unsigned long index;
 
 	dev_info(&pdev->dev, "Resetting PCI slot\n");
@@ -870,6 +878,13 @@ static pci_ers_result_t intel_vsec_pci_slot_reset(struct pci_dev *pdev)
 		devm_release_action(&pdev->dev, intel_vsec_remove_aux,
 				    &intel_vsec_dev->auxdev);
 	}
+
+	/*
+	 * intel_vsec_pci_init() reuses priv. Reset the registration state
+	 * after tearing down old aux devices or the rewalk will skip them as
+	 * already registered.
+	 */
+	intel_vsec_reset_state(priv);
 	pci_restore_state(pdev);
 	intel_vsec_pci_init(pdev);
 
-- 
2.43.0