[PATCH net] tg3: Invert restart quirk logic to restrict SNP power-down bypass

["Noam D. Eliyahu" <noam.d.eliyahu@gmail.com>]

Commit 9fc3bc764334 ("tg3: power down device only on SYSTEM_POWER_OFF")
bypassed `tg3_power_down()` on system restarts to prevent reboot hangs and
NMIs on servers where NICs were initialized via SNP (such as Dell PowerEdge
R650 and R750).

However, skipping the power-down flow globally causes the ACPI _PTS method
to trigger fatal PCIe AER events and hangs on other models. Commit
e0efe83ed325 ("tg3: Disable tg3 PCIe AER on system reboot") attempted to
mitigate this by adding an AER-disable DMI quirk table. Maintaining a
growing list of models for a secondary symptom misses the root cause,
leaving systems like the PowerEdge T440 (sharing the BCM5720 NIC) exposed.

Fix this by inverting the quirk logic:
1. Restrict SNP power-down avoidance strictly to
   `tg3_restart_snp_quirk_table` for the specific systems requiring it
   (Dell PowerEdge R650 and R750).
2. Restore standard power-down behavior for all other systems, eliminating
   the separate AER-disable quirk table.

For systems affected by the original SNP restart issue, their shutdown flow
remains completely untouched.

Link: https://lore.kernel.org/netdev/20251221175050.14089-1-noam.d.eliyahu@gmail.com/T/#u
Fixes: 9fc3bc764334 ("tg3: power down device only on SYSTEM_POWER_OFF")
Fixes: e0efe83ed325 ("tg3: Disable tg3 PCIe AER on system reboot")
Cc: stable@vger.kernel.org
Signed-off-by: Noam D. Eliyahu <noam.d.eliyahu@gmail.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 48 +++++++----------------------
 1 file changed, 11 insertions(+), 37 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index ce108705bbaf..95827df4cf6a 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -18256,53 +18256,23 @@ static int tg3_resume(struct device *device)
 
 static SIMPLE_DEV_PM_OPS(tg3_pm_ops, tg3_suspend, tg3_resume);
 
-/* Systems where ACPI _PTS (Prepare To Sleep) S5 will result in a fatal
- * PCIe AER event on the tg3 device if the tg3 device is not, or cannot
- * be, powered down.
+/* Systems where powering down a tg3 device on restarts triggers
+ * NMIs and fatal hangs during reboot if the network adapters were
+ * initialized under SNP.
  */
-static const struct dmi_system_id tg3_restart_aer_quirk_table[] = {
-	{
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R440"),
-		},
-	},
-	{
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R540"),
-		},
-	},
-	{
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R640"),
-		},
-	},
+static const struct dmi_system_id tg3_restart_snp_quirk_table[] = {
 	{
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R650"),
 		},
 	},
-	{
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R740"),
-		},
-	},
 	{
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R750"),
 		},
 	},
-	{
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "datto"),
-			DMI_MATCH(DMI_PRODUCT_NAME, "SIRIS 5 1U Server"),
-		},
-	},
 	{}
 };
 
@@ -18320,14 +18290,18 @@ static void tg3_shutdown(struct pci_dev *pdev)
 	if (netif_running(dev))
 		dev_close(dev);
 
-	if (system_state == SYSTEM_POWER_OFF)
+	if (!dmi_first_match(tg3_restart_snp_quirk_table) ||
+	    system_state == SYSTEM_POWER_OFF) {
 		tg3_power_down(tp);
-	else if (system_state == SYSTEM_RESTART &&
-		 dmi_first_match(tg3_restart_aer_quirk_table) &&
+	} else if (system_state == SYSTEM_RESTART &&
 		 pdev->current_state != PCI_D3cold &&
 		 pdev->current_state != PCI_UNKNOWN) {
 		/* Disable PCIe AER on the tg3 to avoid a fatal
 		 * error during this system restart.
+		 * Needed since on restarts for systems in
+		 * tg3_restart_snp_quirk_table skipping on powering down the
+		 * tg3 device causes a fatal AER error during ACPI _PTS
+		 * (Prepare To Sleep).
 		 */
 		pcie_capability_clear_word(pdev, PCI_EXP_DEVCTL,
 					   PCI_EXP_DEVCTL_CERE |
-- 
2.39.5