net: atlantic: always deep reset on pm op, fixing null deref regression

From 86ba48e4c5e1b34cea471b8f5a64b085763e0c57 Mon Sep 17 00:00:00 2001
From: Manuel Ullmann <[email protected]>
Date: Wed, 4 May 2022 21:30:44 +0200

The impact of this regression is the same for resume that I saw on
thaw: the kernel hangs and nothing except SysRq rebooting can be done.

The null deref occurs at the same position as on thaw.

BUG: kernel NULL pointer dereference
RIP: aq_ring_rx_fill+0xcf/0x210 [atlantic]

Fixes regression in cbe6c3a8f8f4 ("net: atlantic: invert deep par in pm functions, preventing null derefs"), where I disabled deep pm resets in suspend and resume, trying to make sense of the atl_resume_common deep parameter in the first place.

It turns out, that atlantic always has to deep reset on pm operations and the parameter is useless. Even though I expected that and tested resume, I screwed up by kexec-rebooting into an unpatched kernel, thus missing the breakage.

This fixup obsoletes the deep parameter of atl_resume_common, but I leave the cleanup for the maintainers to post to mainline.

PS: I'm very sorry for this regression.

Changes in v2:
Patch formatting fixes
- Fix Fixes tag
– Simplify stable Cc tag
– Fix Signed-off-by tag

---
 drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 3a529ee8c834..831833911a52 100644
@@ -449,7 +449,7 @@ static int aq_pm_freeze(struct device *dev)
 
 static int aq_pm_suspend_poweroff(struct device *dev)
 {
-	return aq_suspend_common(dev, false);
+	return aq_suspend_common(dev, true);
 }
 
 static int aq_pm_thaw(struct device *dev)

@@ -459,7 +459,7 @@ static int aq_pm_thaw(struct device *dev)
 
 static int aq_pm_resume_restore(struct device *dev)
 {
-	return atl_resume_common(dev, false);
+	return atl_resume_common(dev, true);
 }
 
 static const struct dev_pm_ops aq_pm_ops = {

base-commit: 672c0c5173427e6b3e2a9bbb7be51ceeec78093a

2.35.1