From: "Guilherme G. Piccoli" <gpicc...@linux.vnet.ibm.com> Date: Mon, 10 Jul 2017 10:55:46 -0300
> Since the introduction of ULD (Upper-Layer Drivers), the MSI-X > deallocating path changed in cxgb4: the driver frees the interrupts > of ULD when unregistering it or on shutdown PCI handler. > > Problem is that if a MSI-X is not freed before deallocated in the PCI > layer, it will trigger a BUG() due to still "alive" interrupt being > tentatively quiesced. > > The below trace was observed when doing a simple unbind of Chelsio's > adapter PCI function, like: > "echo 001e:80:00.4 > /sys/bus/pci/drivers/cxgb4/unbind" > > Trace: > > kernel BUG at drivers/pci/msi.c:352! > Oops: Exception in kernel mode, sig: 5 [#1] > ... > NIP [c0000000005a5e60] free_msi_irqs+0xa0/0x250 > LR [c0000000005a5e50] free_msi_irqs+0x90/0x250 > Call Trace: > [c0000000005a5e50] free_msi_irqs+0x90/0x250 (unreliable) > [c0000000005a72c4] pci_disable_msix+0x124/0x180 > [d000000011e06708] disable_msi+0x88/0xb0 [cxgb4] > [d000000011e06948] free_some_resources+0xa8/0x160 [cxgb4] > [d000000011e06d60] remove_one+0x170/0x3c0 [cxgb4] > [c00000000058a910] pci_device_remove+0x70/0x110 > [c00000000064ef04] device_release_driver_internal+0x1f4/0x2c0 > ... > > This patch fixes the issue by refactoring the shutdown path of ULD on > cxgb4 driver, by properly freeing and disabling interrupts on PCI > remove handler too. > > Fixes: 0fbc81b3ad51 ("Allocate resources dynamically for all cxgb4 ULD's") > Reported-by: Harsha Thyagaraja <hathy...@in.ibm.com> > Signed-off-by: Guilherme G. Piccoli <gpicc...@linux.vnet.ibm.com> Applied and queued up for -stable, thanks.