Re: [PATCH 2/3] pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts
From: Gavin Shan <hidden>
Date: 2017-02-16 05:51:27
Also in:
linux-pci, stable
On Thu, Feb 16, 2017 at 03:31:48PM +1100, Andrew Donnellan wrote:
On 16/02/17 10:22, Gavin Shan wrote:quoted
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: <redacted> # v4.9+ Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Signed-off-by: Gavin Shan <redacted>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