Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <7b909a56-1b3d-79fb-0286-b10117982dc3@linaro.org>
Date:   Mon, 26 Jun 2023 14:46:20 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.12.0
Subject: Re: [PATCH] arm64: dts: qcom: sm8350: fix BAM DMA crash and reboot
Content-Language: en-US
To:     Luca Weiss <luca.weiss@fairphone.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Bhupesh Sharma <bhupesh.sharma@linaro.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
References: <20230621143627.189134-1-krzysztof.kozlowski@linaro.org>
 <CTMJRMN2K8AY.20TQJE584A453@otso>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <CTMJRMN2K8AY.20TQJE584A453@otso>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 26/06/2023 13:32, Luca Weiss wrote:
> Hi Krzysztof,
> 
> On Wed Jun 21, 2023 at 4:36 PM CEST, Krzysztof Kozlowski wrote:
>> SM8350 HDK and MTP boards were silently dying and rebooting during BAM
>> DMA probe:
>>
>>   [    1.574304] vreg_bob: Setting 3008000-3960000uV
>>   [    1.576918] bam-dFormat: Log Type - Time(microsec) - Message -
>>   Optional Info
>>   Log Type: B - Since Boot(Power On Reset),  D - Delta,  S - Statistic
>>   S - QC_IMAGE_VERSION_STRING=BOOT.MXF.1.0-00637.1-LAHAINA-1
>>   S - IMAGE_VARIANT_STRING=SocLahainaLAA
>>   S - OEM_IMAGE_VERSION_STRING=crm-ubuntu77
>>   S - Boot Interface: UFS
>>
>> It seems that BAM DMA is locally controller (not by firmware) and
>> requires proper initialization by the driver prior to use, at least on
>> HDK8350 and MTP8350, but probably on all boards.
> 
> Are you sure that the bam (and subsequent the qce) actually probes with
> this change? From reading the code I don't see how the bam should probe
> without either qcom,controlled-remotely or qcom,powered-remotely but no

Why the binding does not require either this or that? Eh, buggy stuff...


> clocks supplied. I think the probe just fails with this change, right?

I will need to double check. I was happy enough to be able to boot my
device instead of having crashes, but indeed it would be nice to fix it
fully.


Best regards,
Krzysztof