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[1/3] pci/hotplug/pnv-php: Remove WARN_ON() in pnv_php_put_slot()

Message ID 1487200954-14681-2-git-send-email-gwshan@linux.vnet.ibm.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Gavin Shan Feb. 15, 2017, 11:22 p.m. UTC
The WARN_ON() causes unnecessary backtrace when putting the parent
slot, which is likely to be NULL.

 WARNING: CPU: 2 PID: 1071 at drivers/pci/hotplug/pnv_php.c:85 \
                              pnv_php_release+0xcc/0x150 [pnv_php]
    :
 Call Trace:
 [c0000003bc007c10] [d00000000ad613c4] pnv_php_release+0x144/0x150 [pnv_php]
 [c0000003bc007c40] [c0000000006641d8] pci_hp_deregister+0x238/0x330
 [c0000003bc007cd0] [d00000000ad61440] pnv_php_unregister_one+0x70/0xa0 [pnv_php]
 [c0000003bc007d10] [d00000000ad614c0] pnv_php_unregister+0x50/0x80 [pnv_php]
 [c0000003bc007d40] [d00000000ad61e84] pnv_php_exit+0x50/0xcb4 [pnv_php]
 [c0000003bc007d70] [c00000000019499c] SyS_delete_module+0x1fc/0x2a0
 [c0000003bc007e30] [c00000000000b184] system_call+0x38/0xe0

Cc: <stable@vger.kernel.org> # v4.8+
Fixes: 66725152fb9f ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver")
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 drivers/pci/hotplug/pnv_php.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Andrew Donnellan Feb. 16, 2017, 4:46 a.m. UTC | #1
On 16/02/17 10:22, Gavin Shan wrote:
> The WARN_ON() causes unnecessary backtrace when putting the parent
> slot, which is likely to be NULL.
>
>  WARNING: CPU: 2 PID: 1071 at drivers/pci/hotplug/pnv_php.c:85 \
>                               pnv_php_release+0xcc/0x150 [pnv_php]
>     :
>  Call Trace:
>  [c0000003bc007c10] [d00000000ad613c4] pnv_php_release+0x144/0x150 [pnv_php]
>  [c0000003bc007c40] [c0000000006641d8] pci_hp_deregister+0x238/0x330
>  [c0000003bc007cd0] [d00000000ad61440] pnv_php_unregister_one+0x70/0xa0 [pnv_php]
>  [c0000003bc007d10] [d00000000ad614c0] pnv_php_unregister+0x50/0x80 [pnv_php]
>  [c0000003bc007d40] [d00000000ad61e84] pnv_php_exit+0x50/0xcb4 [pnv_php]
>  [c0000003bc007d70] [c00000000019499c] SyS_delete_module+0x1fc/0x2a0
>  [c0000003bc007e30] [c00000000000b184] system_call+0x38/0xe0
>
> Cc: <stable@vger.kernel.org> # v4.8+
> Fixes: 66725152fb9f ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver")
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Vaibhav Jain Feb. 16, 2017, 6:10 a.m. UTC | #2
Andrew Donnellan <andrew.donnellan@au1.ibm.com> writes:
>> Cc: <stable@vger.kernel.org> # v4.8+
>> Fixes: 66725152fb9f ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver")
>> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>
> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Tested-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Michael Ellerman Feb. 19, 2017, 11:33 a.m. UTC | #3
On Wed, 2017-02-15 at 23:22:32 UTC, Gavin Shan wrote:
> The WARN_ON() causes unnecessary backtrace when putting the parent
> slot, which is likely to be NULL.
> 
>  WARNING: CPU: 2 PID: 1071 at drivers/pci/hotplug/pnv_php.c:85 \
>                               pnv_php_release+0xcc/0x150 [pnv_php]
>     :
>  Call Trace:
>  [c0000003bc007c10] [d00000000ad613c4] pnv_php_release+0x144/0x150 [pnv_php]
>  [c0000003bc007c40] [c0000000006641d8] pci_hp_deregister+0x238/0x330
>  [c0000003bc007cd0] [d00000000ad61440] pnv_php_unregister_one+0x70/0xa0 [pnv_php]
>  [c0000003bc007d10] [d00000000ad614c0] pnv_php_unregister+0x50/0x80 [pnv_php]
>  [c0000003bc007d40] [d00000000ad61e84] pnv_php_exit+0x50/0xcb4 [pnv_php]
>  [c0000003bc007d70] [c00000000019499c] SyS_delete_module+0x1fc/0x2a0
>  [c0000003bc007e30] [c00000000000b184] system_call+0x38/0xe0
> 
> Cc: <stable@vger.kernel.org> # v4.8+
> Fixes: 66725152fb9f ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver")
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
> Tested-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/36c7c9da40c408a71e5e6bfe12e57d

cheers
diff mbox

Patch

diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index 63cd9f3..da1bbf3 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -76,7 +76,7 @@  static void pnv_php_free_slot(struct kref *kref)
 static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot)
 {
 
-	if (WARN_ON(!php_slot))
+	if (!php_slot)
 		return;
 
 	kref_put(&php_slot->kref, pnv_php_free_slot);