Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [Discussion] Uninitialized variable in wiz_mode_select()
To:     Muhammad Usama Anjum <musamaanjum@gmail.com>,
        Vinod Koul <vkoul@kernel.org>,
        "open list:GENERIC PHY FRAMEWORK" <linux-phy@lists.infradead.org>,
        open list <linux-kernel@vger.kernel.org>,
        <kernel-janitors@vger.kernel.org>, <colin.king@canonical.com>,
        <dan.carpenter@oracle.com>
References: <943b92c6ac291726cf0e6bd92e88f2110c14b74c.camel@gmail.com>
From:   Kishon Vijay Abraham I <kishon@ti.com>
Message-ID: <aaa035d2-95a7-00b3-ef76-1aa61c7f8da9@ti.com>
Date:   Thu, 1 Apr 2021 13:08:21 +0530
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <943b92c6ac291726cf0e6bd92e88f2110c14b74c.camel@gmail.com>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi Usama,

On 01/04/21 1:03 pm, Muhammad Usama Anjum wrote:
> Hi,
> 
> `mode` remains uninitialized when `lane_phy_type` isn't PHY_TYPE_DP
> or 
> PHY_TYPE_QSGMII. I've checked the dtsi (k3-j721e-common-proc-
> board.dts) 
> and possible values of `lane_phy_type` are justPHY_TYPE_USB3 and 
> PHY_TYPE_PCIE. If this is correct, the mode will remain uninitialized with
> garbage value. `mode` should be initialized to what? It seems like it is highly 
> implementation dependent.
> 
> /drivers/phy/ti/phy-j721e-wiz.c: 344 in wiz_mode_select()
> 338             for (i = 0; i < num_lanes; i++) {
> 339                     if (wiz->lane_phy_type[i] == PHY_TYPE_DP)
> 340                             mode = LANE_MODE_GEN1;
> 341                     else if (wiz->lane_phy_type[i] == PHY_TYPE_QSGMII)
> 342                             mode = LANE_MODE_GEN2;
> 343     
>>>>     CID 1503592:  Uninitialized variables  (UNINIT)
>>>>     Using uninitialized value "mode" when calling "regmap_field_write".
> 344                     ret = regmap_field_write(wiz->p_standard_mode[i], mode);
> 345                     if (ret)
> 346                             return ret;
> 347             }
> 348     
> 349             return 0;

I've sent a follow-up patch fixing this.
http://lor.kernel.org/r/20210331131417.15596-1-kishon@ti.com

Thanks
Kishon