[PATCH] thunderbolt: nhi: Don't act on random stack values
From: Konrad Dybcio
Date: Mon Mar 09 2026 - 05:42:40 EST
From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
device_property_read_foo() returns 0 on success and only then modifies
'val'. Currently, val is left uninitialized if the aforementioned
function returns non-zero, making nhi_wake_supported() return true
almost always (random != 0) if the property is not present in device
firmware.
Invert the check to make it make sense.
Note device_property_read_bool() would not be fitting here, as both
0 and (presumably) 1 seem to be acceptable values if the property is
present at all.
Fixes: 3cdb9446a117 ("thunderbolt: Add support for Intel Ice Lake")
Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
---
drivers/thunderbolt/nhi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index ccce020a2432..2bb2e79ca3cb 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -1020,7 +1020,7 @@ static bool nhi_wake_supported(struct pci_dev *pdev)
* If power rails are sustainable for wakeup from S4 this
* property is set by the BIOS.
*/
- if (device_property_read_u8(&pdev->dev, "WAKE_SUPPORTED", &val))
+ if (!device_property_read_u8(&pdev->dev, "WAKE_SUPPORTED", &val))
return !!val;
return true;
---
base-commit: fc7b1a72c6cd5cbbd989c6c32a6486e3e4e3594d
change-id: 20260309-topic-tbt_fixup-407e9a7814f6
Best regards,
--
Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>