Re: Reported regressions for 4.7 as of Sunday, 2016-06-19
From: Johannes Thumshirn
Date: Thu Jun 23 2016 - 03:22:47 EST
[+ Cc linux-scsi@xxxxxxxxxxxxxxx ]
On Wed, Jun 22, 2016 at 03:57:35PM +0000, Quinn Tran wrote:
> Johannes, Martin,
>
> Based on the screen shot/call trace, it looks like this adapter is not using MSIX. It defaulted back to MSI or INTx interrupt. The code made an assumption of MSIX is available. There is no point in go through that code segment.
>
> Can you try this work around? Itâs untested. Thanks.
>
>
> diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
> index 5649c20..e033ecb 100644
> --- a/drivers/scsi/qla2xxx/qla_isr.c
> +++ b/drivers/scsi/qla2xxx/qla_isr.c
> @@ -2548,7 +2548,7 @@ void qla24xx_process_response_queue(struct scsi_qla_host *vha,
> if (!vha->flags.online)
> return;
>
> - if (rsp->msix->cpuid != smp_processor_id()) {
> + if (rsp->msix && (rsp->msix->cpuid != smp_processor_id())) {
> /* if kernel does not notify qla of IRQ's CPU change,
> * then set it here.
> */
>
But this still does not fix the race which would be possible if the HBA is
using MSI-X but triggering IRQs early enough.
Have a look at this (I admit theoretical) path:
qla24xx_enable_msix(struct qla_hw_data *ha, struct rsp_que *rsp)
{
[...]
/* Enable MSI-X vectors for the base queue */
for (i = 0; i < 2; i++) {
qentry = &ha->msix_entries[i];
if (IS_P3P_TYPE(ha))
ret = request_irq(qentry->vector,
qla82xx_msix_entries[i].handler,
0, qla82xx_msix_entries[i].name, rsp);
else
ret = request_irq(qentry->vector,
msix_entries[i].handler,
0, msix_entries[i].name, rsp);
if (ret)
goto msix_register_fail;
<--- IRQ arrives here
qentry->have_irq = 1;
qentry->rsp = rsp;
rsp->msix = qentry;
[...]
void qla24xx_process_response_queue(struct scsi_qla_host *vha,
struct rsp_que *rsp)
{
[...]
if (rsp->msix->cpuid != smp_processor_id()) {
^
\--- rsp->msix == NULL
/* if kernel does not notify qla of IRQ's CPU change,
* then set it here.
*/
rsp->msix->cpuid = smp_processor_id();
ha->tgt.rspq_vector_cpuid = rsp->msix->cpuid;
--
Johannes Thumshirn Storage
jthumshirn@xxxxxxx +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 NÃrnberg
GF: Felix ImendÃrffer, Jane Smithard, Graham Norton
HRB 21284 (AG NÃrnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850