RE: [PATCH] Do not fire MR_DCMD_PD_LIST_QUERY to controllers which do not support it

[Sumit Saxena <sumit.saxena@broadcom.com>]

Please ignore this patch. I missed to add megaraid_sas in subject line. I
realized after sending. Will be resending with proper subject. Sorry for
spamming.

> -----Original Message-----
> From: Sumit Saxena [mailto:sumit.saxena@broadcom.com]
> Sent: Friday, July 08, 2016 3:51 PM
> To: James.Bottomley@HansenPartnership.com; martin.petersen@oracle.com
> Cc: linux-scsi@vger.kernel.org; kashyap.desai@broadcom.com;
> lucz@geza.com; stable@vger.kernel.org; Sumit Saxena
> Subject: [PATCH] Do not fire MR_DCMD_PD_LIST_QUERY to controllers which
> do not support it
>
> There was an issue reported by Lucz Geza on Dell Perc 6i. As per issue
> reported,
> driver goes into an infinite error reporting loop as soon as there is a
> change in
> the status of one of the arrays (degrade, resync online etc …).
> Below are the error logs reported continuously-
>
> Jun 25 08:49:30 ns8 kernel: [  757.757017] megaraid_sas 0000:02:00.0: DCMD
> failed/not supported by firmware: megasas_get_pd_list 4115 Jun 25 08:49:30
> ns8 kernel: [  757.778017] megaraid_sas 0000:02:00.0: DCMD failed/not
> supported by firmware: megasas_get_pd_list 4115 Jun 25 08:49:30 ns8
> kernel: [
> 757.799017] megaraid_sas 0000:02:00.0: DCMD failed/not supported by
> firmware: megasas_get_pd_list 4115 Jun 25 08:49:30 ns8 kernel: [
> 757.820018]
> megaraid_sas 0000:02:00.0: DCMD failed/not supported by firmware:
> megasas_get_pd_list 4115 Jun 25 08:49:30 ns8 kernel: [  757.841018]
> megaraid_sas 0000:02:00.0: DCMD failed/not supported by firmware:
> megasas_get_pd_list 4115
>
> This issue is very much specific to controllers which do not support DCMD-
> MR_DCMD_PD_LIST_QUERY.
> In case of any hotplugging/rescanning of drives, AEN thread will be
> scheduled by
> driver and fire
> DCMD- MR_DCMD_PD_LIST_QUERY and if this DCMD is failed then driver will
> fail this event processing and will not go ahead for further events. This
> will cause
> infinite loop of same event getting retried infinitely and causing above
> mentioned logs.
>
> Fix for this problem is: not to fire DCMD MR_DCMD_PD_LIST_QUERY for
> controllers which do not support it and send DCMD SUCCESS status to AEN
> function so that it can go ahead with other event processing.
>
> Reported-by: Lucz Geza <geza@lucz.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
>
> ---
>  drivers/scsi/megaraid/megaraid_sas_base.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c
> b/drivers/scsi/megaraid/megaraid_sas_base.c
> index f4b0690..2dab3dc 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
> @@ -4079,6 +4079,12 @@ megasas_get_pd_list(struct megasas_instance
> *instance)
>  	struct MR_PD_ADDRESS *pd_addr;
>  	dma_addr_t ci_h = 0;
>
> +	if (instance->pd_list_not_supported) {
> +		dev_info(&instance->pdev->dev, "MR_DCMD_PD_LIST_QUERY
> "
> +		"not supported by firmware\n");
> +		return ret;
> +	}
> +
>  	cmd = megasas_get_cmd(instance);
>
>  	if (!cmd) {
> --
> 2.4.11