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[2/3] pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts

Message ID 1487200954-14681-3-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 root port or PCIe switch downstream port might have been associated
with driver other than pnv-php. The MSI or MSIx might also have been
enabled by that driver (e.g. pcieport_drv). Attempt to enable MSI incurs
below backtrace:

 PowerPC PowerNV PCI Hotplug Driver version: 0.1
 ------------[ cut here ]------------
 WARNING: CPU: 19 PID: 1004 at drivers/pci/msi.c:1071 \
                              __pci_enable_msi_range+0x84/0x4e0
 NIP [c000000000665c34] __pci_enable_msi_range+0x84/0x4e0
 LR [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
 Call Trace:
 [c000000384d67600] [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
 [c000000384d676e0] [d00000000aa31b04] pnv_php_register+0x564/0x5a0 [pnv_php]
 [c000000384d677c0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
 [c000000384d678a0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
 [c000000384d67980] [d00000000aa31dfc] pnv_php_init+0x60/0x98 [pnv_php]
 [c000000384d679f0] [c00000000000cfdc] do_one_initcall+0x6c/0x1d0
 [c000000384d67ab0] [c000000000b92354] do_init_module+0x94/0x254
 [c000000384d67b40] [c00000000019719c] load_module+0x258c/0x2c60
 [c000000384d67d30] [c000000000197bb0] SyS_finit_module+0xf0/0x170
 [c000000384d67e30] [c00000000000b184] system_call+0x38/0xe0

This fixes the issue by skipping enabling the surprise hotplug
capability if the MSI or MSIx on the PCI slot's upstream port has
been enabled by other driver.

Cc: <stable@vger.kernel.org> # v4.9+
Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 drivers/pci/hotplug/pnv_php.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Andrew Donnellan Feb. 16, 2017, 4:31 a.m. UTC | #1
On 16/02/17 10:22, Gavin Shan wrote:
> The root port or PCIe switch downstream port might have been associated
> with driver other than pnv-php. The MSI or MSIx might also have been
> enabled by that driver (e.g. pcieport_drv). Attempt to enable MSI incurs
> below backtrace:
>
>  PowerPC PowerNV PCI Hotplug Driver version: 0.1
>  ------------[ cut here ]------------
>  WARNING: CPU: 19 PID: 1004 at drivers/pci/msi.c:1071 \
>                               __pci_enable_msi_range+0x84/0x4e0
>  NIP [c000000000665c34] __pci_enable_msi_range+0x84/0x4e0
>  LR [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
>  Call Trace:
>  [c000000384d67600] [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
>  [c000000384d676e0] [d00000000aa31b04] pnv_php_register+0x564/0x5a0 [pnv_php]
>  [c000000384d677c0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
>  [c000000384d678a0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
>  [c000000384d67980] [d00000000aa31dfc] pnv_php_init+0x60/0x98 [pnv_php]
>  [c000000384d679f0] [c00000000000cfdc] do_one_initcall+0x6c/0x1d0
>  [c000000384d67ab0] [c000000000b92354] do_init_module+0x94/0x254
>  [c000000384d67b40] [c00000000019719c] load_module+0x258c/0x2c60
>  [c000000384d67d30] [c000000000197bb0] SyS_finit_module+0xf0/0x170
>  [c000000384d67e30] [c00000000000b184] system_call+0x38/0xe0
> 360aebd85a4c
> This fixes the issue by skipping enabling the surprise hotplug
> capability if the MSI or MSIx on the PCI slot's upstream port has
> been enabled by other driver.
>
> Cc: <stable@vger.kernel.org> # v4.9+
> Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

Should this print something to the kernel log to indicate that surprise 
hotplug is unavailable?

Otherwise:

Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Gavin Shan Feb. 16, 2017, 5:50 a.m. UTC | #2
On Thu, Feb 16, 2017 at 03:31:48PM +1100, Andrew Donnellan wrote:
>On 16/02/17 10:22, Gavin Shan wrote:
>>The root port or PCIe switch downstream port might have been associated
>>with driver other than pnv-php. The MSI or MSIx might also have been
>>enabled by that driver (e.g. pcieport_drv). Attempt to enable MSI incurs
>>below backtrace:
>>
>> PowerPC PowerNV PCI Hotplug Driver version: 0.1
>> ------------[ cut here ]------------
>> WARNING: CPU: 19 PID: 1004 at drivers/pci/msi.c:1071 \
>>                              __pci_enable_msi_range+0x84/0x4e0
>> NIP [c000000000665c34] __pci_enable_msi_range+0x84/0x4e0
>> LR [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
>> Call Trace:
>> [c000000384d67600] [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
>> [c000000384d676e0] [d00000000aa31b04] pnv_php_register+0x564/0x5a0 [pnv_php]
>> [c000000384d677c0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
>> [c000000384d678a0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
>> [c000000384d67980] [d00000000aa31dfc] pnv_php_init+0x60/0x98 [pnv_php]
>> [c000000384d679f0] [c00000000000cfdc] do_one_initcall+0x6c/0x1d0
>> [c000000384d67ab0] [c000000000b92354] do_init_module+0x94/0x254
>> [c000000384d67b40] [c00000000019719c] load_module+0x258c/0x2c60
>> [c000000384d67d30] [c000000000197bb0] SyS_finit_module+0xf0/0x170
>> [c000000384d67e30] [c00000000000b184] system_call+0x38/0xe0
>>360aebd85a4c
>>This fixes the issue by skipping enabling the surprise hotplug
>>capability if the MSI or MSIx on the PCI slot's upstream port has
>>been enabled by other driver.
>>
>>Cc: <stable@vger.kernel.org> # v4.9+
>>Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
>>Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>
>Should this print something to the kernel log to indicate that surprise
>hotplug is unavailable?
>

I don't think it's necessary as the situation can be known from lspci
and /proc/interrupts easily. Otherwise, we could add pr_warn_once()
to print the warning message for once, not on all slots.

Thanks,
Gavin
Vaibhav Jain Feb. 16, 2017, 6:11 a.m. UTC | #3
Andrew Donnellan <andrew.donnellan@au1.ibm.com> writes:

>>
>> Cc: <stable@vger.kernel.org> # v4.9+
>> Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv 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>
diff mbox

Patch

diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index da1bbf3..6d36b76 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -826,6 +826,14 @@  static void pnv_php_enable_irq(struct pnv_php_slot *php_slot)
 	struct pci_dev *pdev = php_slot->pdev;
 	int irq, ret;
 
+	/*
+	 * The MSI/MSIx interrupt might have been occupied by other
+	 * drivers. Don't populate the surprise hotplug capability
+	 * in that case.
+	 */
+	if (pci_dev_msi_enabled(pdev))
+		return;
+
 	ret = pci_enable_device(pdev);
 	if (ret) {
 		dev_warn(&pdev->dev, "Error %d enabling device\n", ret);