Re: [RFC PATCH v2 14/18] gpu: host1x: mipi: Split tegra_mipi_calibrate and tegra_mipi_wait

From: Dmitry Osipenko <digetx@gmail.com>
To: Sowjanya Komatineni <skomatineni@nvidia.com>,
	thierry.reding@gmail.com, jonathanh@nvidia.com,
	frankc@nvidia.com, hverkuil@xs4all.nl, sakari.ailus@iki.fi,
	robh+dt@kernel.org, helen.koike@collabora.com
Cc: sboyd@kernel.org, gregkh@linuxfoundation.org,
	linux-media@vger.kernel.org, devicetree@vger.kernel.org,
	linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-i2c@vger.kernel.org
Subject: Re: [RFC PATCH v2 14/18] gpu: host1x: mipi: Split tegra_mipi_calibrate and tegra_mipi_wait
Date: Thu, 18 Jun 2020 03:35:20 +0300	[thread overview]
Message-ID: <457e3754-c783-0ec4-068c-8b5f5ff8de0a@gmail.com> (raw)
In-Reply-To: <1592358094-23459-15-git-send-email-skomatineni@nvidia.com>

17.06.2020 04:41, Sowjanya Komatineni пишет:
...
> -static int tegra_mipi_wait(struct tegra_mipi *mipi)
> +int tegra_mipi_wait(struct tegra_mipi_device *device)
>  {
> +	struct tegra_mipi *mipi = device->mipi;
>  	unsigned long timeout = jiffies + msecs_to_jiffies(250);
>  	u32 value;
> +	int err;
> +
> +	err = clk_enable(device->mipi->clk);
> +	if (err < 0)
> +		return err;
> +
> +	mutex_lock(&device->mipi->lock);

The timeout variable should be assigned *after* taking the lock.

It will be better if you could use the read_poll_timeout() or
readl_relaxed_poll_timeout() here.

>  	while (time_before(jiffies, timeout)) {
>  		value = tegra_mipi_readl(mipi, MIPI_CAL_STATUS);
>  		if ((value & MIPI_CAL_STATUS_ACTIVE) == 0 &&
>  		    (value & MIPI_CAL_STATUS_DONE) != 0)
> -			return 0;
> +			goto done;
>  
>  		usleep_range(10, 50);
>  	}
>  
> -	return -ETIMEDOUT;
> +	err = -ETIMEDOUT;
> +done:
> +	mutex_unlock(&device->mipi->lock);
> +	clk_disable(device->mipi->clk);
> +	return err;
>  }
> +EXPORT_SYMBOL(tegra_mipi_wait);