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Date:   Fri, 5 Mar 2021 18:44:01 -0600
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Stephen Boyd <swboyd@chromium.org>
Cc:     Andy Gross <agross@kernel.org>, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org,
        Elliot Berman <eberman@codeaurora.org>,
        Brian Masney <masneyb@onstation.org>,
        Stephan Gerhold <stephan@gerhold.net>,
        Jeffrey Hugo <jhugo@codeaurora.org>,
        Douglas Anderson <dianders@chromium.org>
Subject: Re: [PATCH 1/6] firmware: qcom_scm: Make
 __qcom_scm_is_call_available() return bool
Message-ID: <YELQUXSI4J2w/6oO@builder.lan>
References: <20210223214539.1336155-1-swboyd@chromium.org>
 <20210223214539.1336155-2-swboyd@chromium.org>
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On Tue 23 Feb 15:45 CST 2021, Stephen Boyd wrote:

> Make __qcom_scm_is_call_available() return bool instead of int. The
> function has "is" in the name, so it should return a bool to indicate
> the truth of the call being available. Unfortunately, it can return a
> number < 0 which also looks "true", but not all callers expect that and
> thus they think a call is available when really the check to see if the
> call is available failed to figure it out.
> 
> Cc: Elliot Berman <eberman@codeaurora.org>
> Cc: Brian Masney <masneyb@onstation.org>
> Cc: Stephan Gerhold <stephan@gerhold.net>
> Cc: Jeffrey Hugo <jhugo@codeaurora.org>
> Cc: Douglas Anderson <dianders@chromium.org>
> Fixes: 0f206514749b ("scsi: firmware: qcom_scm: Add support for programming inline crypto keys")
> Fixes: 0434a4061471 ("firmware: qcom: scm: add support to restore secure config to qcm_scm-32")
> Fixes: b0a1614fb1f5 ("firmware: qcom: scm: add OCMEM lock/unlock interface")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>

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

Regards,
Bjorn

> ---
>  drivers/firmware/qcom_scm.c | 19 ++++++++-----------
>  1 file changed, 8 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index f57779fc7ee9..2be5573dce53 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -113,9 +113,6 @@ static void qcom_scm_clk_disable(void)
>  	clk_disable_unprepare(__scm->bus_clk);
>  }
>  
> -static int __qcom_scm_is_call_available(struct device *dev, u32 svc_id,
> -					u32 cmd_id);
> -
>  enum qcom_scm_convention qcom_scm_convention;
>  static bool has_queried __read_mostly;
>  static DEFINE_SPINLOCK(query_lock);
> @@ -219,8 +216,8 @@ static int qcom_scm_call_atomic(struct device *dev,
>  	}
>  }
>  
> -static int __qcom_scm_is_call_available(struct device *dev, u32 svc_id,
> -					u32 cmd_id)
> +static bool __qcom_scm_is_call_available(struct device *dev, u32 svc_id,
> +					 u32 cmd_id)
>  {
>  	int ret;
>  	struct qcom_scm_desc desc = {
> @@ -247,7 +244,7 @@ static int __qcom_scm_is_call_available(struct device *dev, u32 svc_id,
>  
>  	ret = qcom_scm_call(dev, &desc, &res);
>  
> -	return ret ? : res.result[0];
> +	return ret ? false : !!res.result[0];
>  }
>  
>  /**
> @@ -585,9 +582,8 @@ bool qcom_scm_pas_supported(u32 peripheral)
>  	};
>  	struct qcom_scm_res res;
>  
> -	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_PIL,
> -					   QCOM_SCM_PIL_PAS_IS_SUPPORTED);
> -	if (ret <= 0)
> +	if (!__qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_PIL,
> +					  QCOM_SCM_PIL_PAS_IS_SUPPORTED))
>  		return false;
>  
>  	ret = qcom_scm_call(__scm->dev, &desc, &res);
> @@ -1060,17 +1056,18 @@ EXPORT_SYMBOL(qcom_scm_ice_set_key);
>   */
>  bool qcom_scm_hdcp_available(void)
>  {
> +	bool avail;
>  	int ret = qcom_scm_clk_enable();
>  
>  	if (ret)
>  		return ret;
>  
> -	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_HDCP,
> +	avail = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_HDCP,
>  						QCOM_SCM_HDCP_INVOKE);
>  
>  	qcom_scm_clk_disable();
>  
> -	return ret > 0;
> +	return avail;
>  }
>  EXPORT_SYMBOL(qcom_scm_hdcp_available);
>  
> -- 
> https://chromeos.dev
>