[PATCH v3 41/41] cxlflash: Handle spurious interrupts

Matthew R. Ochs mrochs at linux.vnet.ibm.com
Thu Mar 29 02:03:02 AEDT 2018

On Mon, Mar 26, 2018 at 11:35:42AM -0500, Uma Krishnan wrote:
> The following Oops can occur when there is heavy I/O traffic and the host
> is reset by a tool such as sg_reset.
> [c000200fff3fbc90] c00800001690117c process_cmd_doneq+0x104/0x500
>                                        [cxlflash] (unreliable)
> [c000200fff3fbd80] c008000016901648 cxlflash_rrq_irq+0xd0/0x150 [cxlflash]
> [c000200fff3fbde0] c000000000193130 __handle_irq_event_percpu+0xa0/0x310
> [c000200fff3fbea0] c0000000001933d8 handle_irq_event_percpu+0x38/0x90
> [c000200fff3fbee0] c000000000193494 handle_irq_event+0x64/0xb0
> [c000200fff3fbf10] c000000000198ea0 handle_fasteoi_irq+0xc0/0x230
> [c000200fff3fbf40] c00000000019182c generic_handle_irq+0x4c/0x70
> [c000200fff3fbf60] c00000000001794c __do_irq+0x7c/0x1c0
> [c000200fff3fbf90] c00000000002a390 call_do_irq+0x14/0x24
> [c000200e5828fab0] c000000000017b2c do_IRQ+0x9c/0x130
> [c000200e5828fb00] c000000000009b04 h_virt_irq_common+0x114/0x120
> When a context is reset, the pending commands are flushed and the AFU
> is notified. Before the AFU handles this request there could be command
> completion interrupts queued to PHB which are yet to be delivered to the
> context. In this scenario, a context could receive an interrupt for a
> command that has been flushed, leading to a possible crash when the memory
> for the flushed command is accessed.
> To resolve this problem, a boolean will indicate if the hardware queue is
> ready to process interrupts or not. This can be evaluated in the interrupt
> handler before proessing an interrupt.
> Signed-off-by: Uma Krishnan <ukrishn at linux.vnet.ibm.com>

Acked-by: Matthew R. Ochs <mrochs at linux.vnet.ibm.com>

More information about the Linuxppc-dev mailing list