linux-kernel - Re: [PATCH v3 2/4] nvmem: qfprom: Fix up qfprom_disable_fuse

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Date:   Fri, 30 Jul 2021 06:49:10 -0700
From:   Doug Anderson <dianders@...omium.org>
To:     Rajendra Nayak <rnayak@...eaurora.org>
Cc:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>,
        "Ravi Kumar Bokka (Temp)" <rbokka@...eaurora.org>
Subject: Re: [PATCH v3 2/4] nvmem: qfprom: Fix up qfprom_disable_fuse_blowing()
 ordering

Hi,

On Thu, Jul 29, 2021 at 11:46 PM Rajendra Nayak <rnayak@...eaurora.org> wrote:
>
> qfprom_disable_fuse_blowing() disables a bunch of resources,
> and then does a few register writes in the 'conf' address
> space.
> It works perhaps because the resources are needed only for the
> 'raw' register space writes, and that the 'conf' space allows
> read/writes regardless.
> However that makes the code look confusing, so just move the
> register writes before turning off the resources in the
> function.
>
> Signed-off-by: Rajendra Nayak <rnayak@...eaurora.org>
> ---
>  drivers/nvmem/qfprom.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c
> index 81fbad5..b0ca4c6 100644
> --- a/drivers/nvmem/qfprom.c
> +++ b/drivers/nvmem/qfprom.c
> @@ -139,6 +139,9 @@ static void qfprom_disable_fuse_blowing(const struct qfprom_priv *priv,
>  {
>         int ret;
>
> +       writel(old->timer_val, priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
> +       writel(old->accel_val, priv->qfpconf + QFPROM_ACCEL_OFFSET);
> +
>         /*
>          * This may be a shared rail and may be able to run at a lower rate
>          * when we're not blowing fuses.  At the moment, the regulator framework
> @@ -159,9 +162,6 @@ static void qfprom_disable_fuse_blowing(const struct qfprom_priv *priv,
>                          "Failed to set clock rate for disable (ignoring)\n");
>
>         clk_disable_unprepare(priv->secclk);
> -
> -       writel(old->timer_val, priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
> -       writel(old->accel_val, priv->qfpconf + QFPROM_ACCEL_OFFSET);
>  }

I think it doesn't matter since all of these resources are just needed
for burning fuses, but I agree that what you have here makes more
logical sense and makes the function less confusing.

Reviewed-by: Douglas Anderson <dianders@...omium.org>