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Date:   Tue, 11 Oct 2022 11:41:25 +0100
From:   Jonathan Cameron <Jonathan.Cameron@huawei.com>
To:     <ira.weiny@intel.com>
CC:     Dan Williams <dan.j.williams@intel.com>,
        Alison Schofield <alison.schofield@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        "Ben Widawsky" <bwidawsk@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Davidlohr Bueso <dave@stgolabs.net>,
        <linux-kernel@vger.kernel.org>, <linux-cxl@vger.kernel.org>
Subject: Re: [RFC V2 PATCH 01/11] cxl/mbox: Add debug of hardware error code
Message-ID: <20221011114125.00003bd2@huawei.com>
In-Reply-To: <20221010224131.1866246-2-ira.weiny@intel.com>
References: <20221010224131.1866246-1-ira.weiny@intel.com>
        <20221010224131.1866246-2-ira.weiny@intel.com>
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On Mon, 10 Oct 2022 15:41:21 -0700
ira.weiny@intel.com wrote:

> From: Ira Weiny <ira.weiny@intel.com>
> 
> If a mailbox command fails the driver always reports ENXIO.  But this
> may not be enough information to understand why the hardware, or in my
> case Qemu, was failing.
> 
> Add a debug print of the error code returned from the hardware.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Seems very sensible to me.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/cxl/core/mbox.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 16176b9278b4..6c4d024ad0e8 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -181,8 +181,11 @@ int cxl_mbox_send_cmd(struct cxl_dev_state *cxlds, u16 opcode, void *in,
>  	if (rc)
>  		return rc;
>  
> -	if (mbox_cmd.return_code != CXL_MBOX_CMD_RC_SUCCESS)
> +	if (mbox_cmd.return_code != CXL_MBOX_CMD_RC_SUCCESS) {
> +		dev_dbg(cxlds->dev, "MB error : %s\n",
> +			cxl_mbox_cmd_rc2str(&mbox_cmd));
>  		return cxl_mbox_cmd_rc2errno(&mbox_cmd);
> +	}
>  
>  	/*
>  	 * Variable sized commands can't be validated and so it's up to the