Received-SPF: pass (google.com: domain of linux-kernel+bounces-197438-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Message-ID: <c49fe0fa-9924-4ff8-9775-080b7b470d41@acm.org>
Date: Fri, 31 May 2024 13:17:16 -0700
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 3/3] ufs: mcq: Prevent no I/O queue case for MCQ
To: Minwoo Im <minwoo.im@samsung.com>,
 "James E . J . Bottomley" <James.Bottomley@HansenPartnership.com>,
 "Martin K . Petersen" <martin.petersen@oracle.com>
Cc: Alim Akhtar <alim.akhtar@samsung.com>, Avri Altman <avri.altman@wdc.com>,
 gost.dev@samsung.com, linux-scsi@vger.kernel.org,
 linux-kernel@vger.kernel.org, Jeuk Kim <jeuk20.kim@samsung.com>
References: <20240531103821.1583934-1-minwoo.im@samsung.com>
 <CGME20240531104948epcas2p1a70f31cd4a1aa5d36267b4187d75056b@epcas2p1.samsung.com>
 <20240531103821.1583934-4-minwoo.im@samsung.com>
Content-Language: en-US
From: Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20240531103821.1583934-4-minwoo.im@samsung.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

On 5/31/24 03:38, Minwoo Im wrote:
> If hba_maxq equals poll_queues, which means there are no I/O queues
> (HCTX_TYPE_DEFAULT, HCTX_TYPE_READ), the very first hw queue will be
> allocated as HCTX_TYPE_POLL and it will be used as the dev_cmd_queue.
> In this case, device commands such as QUERY cannot be properly handled.
> 
> This patch prevents the initialization of MCQ when the number of I/O
> queues is not set and only the number of POLL queues is set.
> 
> Signed-off-by: Minwoo Im <minwoo.im@samsung.com>
> ---
>   drivers/ufs/core/ufs-mcq.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
> index 46faa54aea94..4bcae410c268 100644
> --- a/drivers/ufs/core/ufs-mcq.c
> +++ b/drivers/ufs/core/ufs-mcq.c
> @@ -179,6 +179,15 @@ static int ufshcd_mcq_config_nr_queues(struct ufs_hba *hba)
>   		return -EOPNOTSUPP;
>   	}
>   
> +	/*
> +	 * Device should support at least one I/O queue to handle device
> +	 * commands via hba->dev_cmd_queue.
> +	 */
> +	if (hba_maxq == poll_queues) {
> +		dev_err(hba->dev, "At least one non-poll queue required\n");
> +		return -EOPNOTSUPP;
> +	}
> +
>   	rem = hba_maxq;
>   
>   	if (rw_queues) {

Reviewed-by: Bart Van Assche <bvanassche@acm.org>