Received-SPF: pass (google.com: domain of linux-kernel+bounces-132283-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Message-ID: <5b7c83f8-2b51-64d8-04c4-49a2047818a5@quicinc.com>
Date: Thu, 4 Apr 2024 17:08:40 -0700
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [PATCH] phy: qcom: qmp-combo: Fix register base for
 QSERDES_DP_PHY_MODE
Content-Language: en-US
To: Stephen Boyd <swboyd@chromium.org>, Vinod Koul <vkoul@kernel.org>,
        "Kishon
 Vijay Abraham I" <kishon@kernel.org>
CC: <linux-kernel@vger.kernel.org>, <patches@lists.linux.dev>,
        <linux-arm-msm@vger.kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        <linux-phy@lists.infradead.org>, <freedreno@lists.freedesktop.org>,
        "Douglas
 Anderson" <dianders@chromium.org>,
        Dmitry Baryshkov
	<dmitry.baryshkov@linaro.org>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Abel Vesa <abel.vesa@linaro.org>, Steev Klimaszewski <steev@kali.org>,
        "Johan
 Hovold" <johan+linaro@kernel.org>,
        Bjorn Andersson
	<quic_bjorande@quicinc.com>
References: <20240405000111.1450598-1-swboyd@chromium.org>
From: Abhinav Kumar <quic_abhinavk@quicinc.com>
In-Reply-To: <20240405000111.1450598-1-swboyd@chromium.org>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit


On 4/4/2024 5:01 PM, Stephen Boyd wrote:
> The register base that was used to write to the QSERDES_DP_PHY_MODE
> register was 'dp_dp_phy' before commit 815891eee668 ("phy:
> qcom-qmp-combo: Introduce orientation variable"). There isn't any
> explanation in the commit why this is changed, so I suspect it was an
> oversight or happened while being extracted from some other series.
> Oddly the value being 0x4c or 0x5c doesn't seem to matter for me, so I
> suspect this is dead code, but that can be fixed in another patch. It's
> not good to write to the wrong register space, and maybe some other
> version of this phy relies on this.
> 
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Cc: Neil Armstrong <neil.armstrong@linaro.org>
> Cc: Abel Vesa <abel.vesa@linaro.org>
> Cc: Steev Klimaszewski <steev@kali.org>
> Cc: Johan Hovold <johan+linaro@kernel.org>
> Cc: Bjorn Andersson <quic_bjorande@quicinc.com>
> Fixes: 815891eee668 ("phy: qcom-qmp-combo: Introduce orientation variable")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>   drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 

Yes I dont know why the commit 815891eee668 ("phy:
  qcom-qmp-combo: Introduce orientation variable") changed the base in 
below code. Certainly looks like a bug to me because we should be 
writing to DP_PHY_MODE which is at an offset 0x1c from the dp_phy base.

Hence, this LGTM,


Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>