Re: [PATCH v4 27/32] cxlflash: Fix to prevent stale AFU RRQ

[Daniel Axtens <dja@axtens.net>]

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"Matthew R. Ochs" <mrochs@linux.vnet.ibm.com> writes:

> Following an adapter reset, the AFU RRQ that resides in host memory
> holds stale data. This can lead to a condition where the RRQ interrupt
> handler tries to process stale entries and/or endlessly loops due to an
> out of sync generation bit.
>
> To fix, the AFU RRQ in host memory needs to be cleared after each reset.

This looks good. Do you need anything to bail out of cxlflash_rrq_irq if
the data goes stale or to all Fs while that function is running?

Daniel

>
> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
> Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
> ---
>  drivers/scsi/cxlflash/main.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
> index 24aedfb..ab11ee6 100644
> --- a/drivers/scsi/cxlflash/main.c
> +++ b/drivers/scsi/cxlflash/main.c
> @@ -1598,6 +1598,9 @@ static int start_afu(struct cxlflash_cfg *cfg)
>=20=20
>  	init_pcr(cfg);
>=20=20
> +	/* After an AFU reset, RRQ entries are stale, clear them */
> +	memset(&afu->rrq_entry, 0, sizeof(afu->rrq_entry));
> +
>  	/* Initialize RRQ pointers */
>  	afu->hrrq_start =3D &afu->rrq_entry[0];
>  	afu->hrrq_end =3D &afu->rrq_entry[NUM_RRQ_ENTRY - 1];
> --=20
> 2.1.0
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