Re: [PATCHv7 0/3] QCOM smmu-500 wait-for-safe handling for sdm845

From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
To: Will Deacon <will@kernel.org>
Cc: bjorn.andersson@linaro.org, Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>,
	iommu@lists.linux-foundation.org,
	Stephen Boyd <swboyd@chromium.org>,
	Vivek Gautam <vivek.gautam@codeaurora.org>,
	linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Rajendra Nayak <rnayak@codeaurora.org>,
	linux-arm-msm-owner@vger.kernel.org,
	Andy Gross <agross@kernel.org>
Subject: Re: [PATCHv7 0/3] QCOM smmu-500 wait-for-safe handling for sdm845
Date: Tue, 05 Nov 2019 07:59:16 +0530	[thread overview]
Message-ID: <8d20a6af33b80191d44db97b757d0dfa@codeaurora.org> (raw)
In-Reply-To: <20191104162339.GD24909@willie-the-truck>

On 2019-11-04 21:53, Will Deacon wrote:
> On Mon, Nov 04, 2019 at 03:15:06PM +0000, Will Deacon wrote:
>> On Sun, Nov 03, 2019 at 11:19:25PM -0600, Andy Gross wrote:
>> > On Fri, Nov 01, 2019 at 11:01:59PM +0530, Sai Prakash Ranjan wrote:
>> > > >>> What's the plan for getting this merged? I'm not happy taking the
>> > > >>> firmware
>> > > >>> bits without Andy's ack, but I also think the SMMU changes should go via
>> > > >>> the IOMMU tree to avoid conflicts.
>> > > >>>
>> > > >>> Andy?
>> > > >>>
>> > > >>
>> > > >>Bjorn maintains QCOM stuff now if I am not wrong and he has already
>> > > >>reviewed
>> > > >>the firmware bits. So I'm hoping you could take all these through IOMMU
>> > > >>tree.
>> > > >
>> > > >Oh, I didn't realise that. Is there a MAINTAINERS update someplace? If I
>> > > >run:
>> > > >
>> > > >$ ./scripts/get_maintainer.pl -f drivers/firmware/qcom_scm-64.c
>> > > >
>> > > >in linux-next, I get:
>> > > >
>> > > >Andy Gross <agross@kernel.org> (maintainer:ARM/QUALCOMM SUPPORT)
>> > > >linux-arm-msm@vger.kernel.org (open list:ARM/QUALCOMM SUPPORT)
>> > > >linux-kernel@vger.kernel.org (open list)
>> > > >
>> > >
>> > > It hasn't been updated yet then. I will leave it to Bjorn or Andy to comment
>> > > on this.
>> >
>> > The rumors of my demise have been greatly exaggerated.  All kidding aside, I
>> > ack'ed both.  Bjorn will indeed be coming on as a co-maintener at some point.
>> > He has already done a lot of yeomans work in helping me out the past 3 months.
>> 
>> Cheers Andy, and I'm pleased to hear that you're still with us! I've 
>> queued
>> this lot for 5.5 and I'll send to Joerg this week.
> 
> Bah, in doing so I spotted that the existing code doesn't handle error 
> codes
> properly because 'a0' is unsigned. I'll queue the patch below at the 
> start
> of the series.
> 
> Will
> 
> --->8
> 
> From a9a1047f08de0eff249fb65e2d5d6f6f8b2a87f0 Mon Sep 17 00:00:00 2001
> From: Will Deacon <will@kernel.org>
> Date: Mon, 4 Nov 2019 15:58:15 +0000
> Subject: [PATCH] firmware: qcom: scm: Ensure 'a0' status code is 
> treated as
>  signed
> 
> The 'a0' member of 'struct arm_smccc_res' is declared as 'unsigned 
> long',
> however the Qualcomm SCM firmware interface driver expects to receive
> negative error codes via this field, so ensure that it's cast to 'long'
> before comparing to see if it is less than 0.
> 
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Will Deacon <will@kernel.org>
> ---
>  drivers/firmware/qcom_scm-64.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/qcom_scm-64.c 
> b/drivers/firmware/qcom_scm-64.c
> index 91d5ad7cf58b..25e0f60c759a 100644
> --- a/drivers/firmware/qcom_scm-64.c
> +++ b/drivers/firmware/qcom_scm-64.c
> @@ -150,7 +150,7 @@ static int qcom_scm_call(struct device *dev, u32
> svc_id, u32 cmd_id,
>  		kfree(args_virt);
>  	}
> 
> -	if (res->a0 < 0)
> +	if ((long)res->a0 < 0)
>  		return qcom_scm_remap_error(res->a0);
> 
>  	return 0;

Fixes: 6b1751a86ce2 ("firmware: qcom: scm: Add support for ARM64 SoCs") 
?

FWIW, Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>

-Sai

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