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Message-ID: <722c57dc-98cf-4ec8-93c5-aef55e6084c7@linaro.org>
Date: Tue, 21 May 2024 19:38:03 +0200
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Subject: Re: [PATCH 6/7] remoteproc: qcom_q6v5_pas: Add hwspinlock bust on
 stop
To: Chris Lew <quic_clew@quicinc.com>, Bjorn Andersson
 <andersson@kernel.org>, Baolin Wang <baolin.wang@linux.alibaba.com>,
 Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>,
 Will Deacon <will@kernel.org>, Waiman Long <longman@redhat.com>,
 Boqun Feng <boqun.feng@gmail.com>, Jonathan Corbet <corbet@lwn.net>,
 Mathieu Poirier <mathieu.poirier@linaro.org>, Rob Herring <robh@kernel.org>,
 Krzysztof Kozlowski <krzk+dt@kernel.org>, Conor Dooley
 <conor+dt@kernel.org>,
 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-doc@vger.kernel.org, linux-arm-msm@vger.kernel.org,
 devicetree@vger.kernel.org, Richard Maina <quic_rmaina@quicinc.com>
References: <20240516-hwspinlock-bust-v1-0-47a90a859238@quicinc.com>
 <20240516-hwspinlock-bust-v1-6-47a90a859238@quicinc.com>
Content-Language: en-US
From: Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <20240516-hwspinlock-bust-v1-6-47a90a859238@quicinc.com>
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On 5/17/24 00:58, Chris Lew wrote:
> From: Richard Maina <quic_rmaina@quicinc.com>
> 
> When remoteproc goes down unexpectedly this results in a state where any
> acquired hwspinlocks will remain locked possibly resulting in deadlock.
> In order to ensure all locks are freed we include a call to
> hwspin_lock_bust() during remoteproc shutdown.
> 
> For qcom_q6v5_pas remoteprocs, each remoteproc has an assigned id that
> is used to take the hwspinlock. Remoteproc should use this id to try and
> bust the lock on remoteproc stop.
> 
> This edge case only occurs with q6v5_pas watchdog crashes. The error
> fatal case has handling to clear the hwspinlock before the error fatal
> interrupt is triggered.
> 
> Signed-off-by: Richard Maina <quic_rmaina@quicinc.com>
> Signed-off-by: Chris Lew <quic_clew@quicinc.com>
> ---


>   drivers/remoteproc/qcom_q6v5_pas.c | 28 ++++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
> 
> diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
> index 54d8005d40a3..57178fcb9aa3 100644
> --- a/drivers/remoteproc/qcom_q6v5_pas.c
> +++ b/drivers/remoteproc/qcom_q6v5_pas.c
> @@ -10,6 +10,7 @@
>   #include <linux/clk.h>
>   #include <linux/delay.h>
>   #include <linux/firmware.h>
> +#include <linux/hwspinlock.h>
>   #include <linux/interrupt.h>
>   #include <linux/kernel.h>
>   #include <linux/module.h>
> @@ -52,6 +53,7 @@ struct adsp_data {
>   	const char *ssr_name;
>   	const char *sysmon_name;
>   	int ssctl_id;
> +	int hwlock_id;
>   
>   	int region_assign_idx;
>   	int region_assign_count;
> @@ -84,6 +86,9 @@ struct qcom_adsp {
>   	bool decrypt_shutdown;
>   	const char *info_name;
>   
> +	struct hwspinlock *hwlock;
> +	int hwlock_id;

IIRC, this is the same one that is passed in the DT.

Can we get it dynamically from there?

Konrad