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Tue, 19 Aug 2025 08:05:15 -0700 (PDT) Date: Tue, 19 Aug 2025 17:05:13 +0200 From: Stephan Gerhold To: Dmitry Baryshkov Cc: Bjorn Andersson , Mathieu Poirier , Sibi Sankar , Abel Vesa , linux-arm-msm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, Konrad Dybcio Subject: Re: [PATCH 2/3] remoteproc: qcom_q6v5: Avoid handling handover twice Message-ID: References: <20250819-rproc-qcom-q6v5-fixes-v1-0-de92198f23c7@linaro.org> <20250819-rproc-qcom-q6v5-fixes-v1-2-de92198f23c7@linaro.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Aug 19, 2025 at 02:41:55PM +0300, Dmitry Baryshkov wrote: > On Tue, Aug 19, 2025 at 01:08:03PM +0200, Stephan Gerhold wrote: > > A remoteproc could theoretically signal handover twice. This is unexpected > > theoretically or practically? > You could easily trigger handover again from a custom remoteproc firmware by setting the handover state to 0 and then back to 1. However, if you find a firmware version doing this, you might want to have a serious conversation with the firmware developer. It makes no sense to do that. :-) In other words, on technical level it is practical. From a conceptual point of view it is just theoretical. In any case, if it happens, we shouldn't mess up reference counters in my opinion (or risk dereferencing invalid pointers etc). Thanks, Stephan