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From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: andy.gross@linaro.org, Sricharan R <sricharan@codeaurora.org>
Cc: patches@linaro.org, linux-arm-msm@vger.kernel.org,
	will.deacon@arm.com, stanimir.varbanov@linaro.org,
	linux-kernel@vger.kernel.org, srinivas.kandagatla@linaro.org,
	catalin.marinas@arm.com, sboyd@codeaurora.org
Subject: Re: [PATCH] firmware: qcom: scm: Fix interrupted SCM calls fully
Date: Wed, 26 Oct 2016 11:35:08 -0700	[thread overview]
Message-ID: <20161026183508.GR7509@tuxbot> (raw)
In-Reply-To: <1475059348-30510-1-git-send-email-sricharan@codeaurora.org>

On Wed 28 Sep 03:42 PDT 2016, Sricharan R wrote:

> Patch [1] fixes the issues with interrupted SCM64 calls
> by returning the register r6 (Session ID) on the next try, but register
> r0 also needs to be preserved for the retry. r0 contains the
> result of the previous try. Without this i see that the SCM calls
> hang when retried.
> 
> [1] https://patchwork.kernel.org/patch/9291589/
> 

Andy, this is needed as well on 8996 - or I get rcu stalls during
firmware loading operations (so I guess it's busy spinning in that
loop).

Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Regards,
Bjorn

> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  drivers/firmware/qcom_scm-64.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
> index 7ecd0e7..28b604e 100755
> --- a/drivers/firmware/qcom_scm-64.c
> +++ b/drivers/firmware/qcom_scm-64.c
> @@ -134,6 +134,9 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
>  		res->a6 = 0;
>  
>  		do {
> +			if (res->a0 == QCOM_SCM_INTERRUPTED)
> +				cmd = res->a0;
> +
>  			arm_smccc_smc(cmd, desc->arginfo, desc->args[0],
>  				      desc->args[1], desc->args[2], x5, res->a6, 0,
>  				      res);
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> 

      reply	other threads:[~2016-10-26 18:35 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-28 10:42 [PATCH] firmware: qcom: scm: Fix interrupted SCM calls fully Sricharan R
2016-10-26 18:35 ` Bjorn Andersson [this message]

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