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

[Daniel Axtens]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

"Matthew R. Ochs" <mrochs at 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 at linux.vnet.ibm.com>
> Signed-off-by: Manoj N. Kumar <manoj at linux.vnet.ibm.com>
> Reviewed-by: Brian King <brking at 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)
>  
>  	init_pcr(cfg);
>  
> +	/* 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 = &afu->rrq_entry[0];
>  	afu->hrrq_end = &afu->rrq_entry[NUM_RRQ_ENTRY - 1];
> -- 
> 2.1.0
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
Comment: GPGTools - https://gpgtools.org
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=O6Zk
-----END PGP SIGNATURE-----