Re: [PATCH 4/5] megaraid_sas: TM command refire leads to controller firmware crash

From: Hannes Reinecke <hare@suse.de>
To: Chandrakanth Patil <chandrakanth.patil@broadcom.com>,
	linux-scsi@vger.kernel.org
Cc: kashyap.desai@broadcom.com, sumit.saxena@broadcom.com,
	kiran-kumar.kasturi@broadcom.com, sankar.patra@broadcom.com,
	sasikumar.pc@broadcom.com,
	shivasharan.srikanteshwara@broadcom.com,
	anand.lodnoor@broadcom.com, stable@vger.kernel.org
Subject: Re: [PATCH 4/5] megaraid_sas: TM command refire leads to controller firmware crash
Date: Wed, 13 May 2020 08:19:57 +0200	[thread overview]
Message-ID: <b007f7ae-0a9d-2bfd-6da8-e72576c40353@suse.de> (raw)
In-Reply-To: <20200508085242.23406-1-chandrakanth.patil@broadcom.com>

On 5/8/20 10:52 AM, Chandrakanth Patil wrote:
> Issue: When TM command times-out driver invokes the controller
> reset. Post reset, driver re-fires pended TM commands which leads
> to firmware crash.
> 
> Fix: Post controller reset, return pended TM commands back to OS.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
> Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
> ---
>   drivers/scsi/megaraid/megaraid_sas_fusion.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> index 87f91a38..319f241 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> @@ -4180,6 +4180,7 @@ static void megasas_refire_mgmt_cmd(struct megasas_instance *instance,
>   	struct fusion_context *fusion;
>   	struct megasas_cmd *cmd_mfi;
>   	union MEGASAS_REQUEST_DESCRIPTOR_UNION *req_desc;
> +	struct MPI2_RAID_SCSI_IO_REQUEST *scsi_io_req;
>   	u16 smid;
>   	bool refire_cmd = false;
>   	u8 result;
> @@ -4247,6 +4248,11 @@ static void megasas_refire_mgmt_cmd(struct megasas_instance *instance,
>   			result = COMPLETE_CMD;
>   		}
>   
> +		scsi_io_req = (struct MPI2_RAID_SCSI_IO_REQUEST *)
> +				cmd_fusion->io_request;
> +		if (scsi_io_req->Function == MPI2_FUNCTION_SCSI_TASK_MGMT)
> +			result = RETURN_CMD;
> +
>   		switch (result) {
>   		case REFIRE_CMD:
>   			megasas_fire_cmd_fusion(instance, req_desc);
> @@ -4475,7 +4481,6 @@ megasas_issue_tm(struct megasas_instance *instance, u16 device_handle,
>   	if (!timeleft) {
>   		dev_err(&instance->pdev->dev,
>   			"task mgmt type 0x%x timed out\n", type);
> -		cmd_mfi->flags |= DRV_DCMD_SKIP_REFIRE;
>   		mutex_unlock(&instance->reset_mutex);
>   		rc = megasas_reset_fusion(instance->host, MFI_IO_TIMEOUT_OCR);
>   		mutex_lock(&instance->reset_mutex);
> 
Why didn't the 'DRV_DCMD_SKIP_REFIRE' work?
And if it doesn't work, can't it be removed completely?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
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