linux-kernel - Re: [PATCH v7 25/34] i2c: tegra: Factor out register polling into separate function

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 21 Sep 2020 13:22:26 +0200
From:   Thierry Reding <thierry.reding@...il.com>
To:     Dmitry Osipenko <digetx@...il.com>
Cc:     Jonathan Hunter <jonathanh@...dia.com>,
        Laxman Dewangan <ldewangan@...dia.com>,
        Wolfram Sang <wsa@...-dreams.de>,
        Michał Mirosław <mirq-linux@...e.qmqm.pl>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        linux-i2c@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 25/34] i2c: tegra: Factor out register polling into
 separate function

On Thu, Sep 17, 2020 at 06:05:41PM +0300, Dmitry Osipenko wrote:
> 17.09.2020 14:58, Thierry Reding пишет:
> > On Wed, Sep 09, 2020 at 01:39:57AM +0300, Dmitry Osipenko wrote:
> >> Factor out register polling into a separate function in order to remove
> >> boilerplate code and make code cleaner.
> >>
> >> Reviewed-by: Michał Mirosław <mirq-linux@...e.qmqm.pl>
> >> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> >> ---
> >>  drivers/i2c/busses/i2c-tegra.c | 57 +++++++++++++++-------------------
> >>  1 file changed, 25 insertions(+), 32 deletions(-)
> >>
> >> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> >> index 405b87e28a98..e071de9ce106 100644
> >> --- a/drivers/i2c/busses/i2c-tegra.c
> >> +++ b/drivers/i2c/busses/i2c-tegra.c
> >> @@ -514,10 +514,24 @@ static void tegra_i2c_vi_init(struct tegra_i2c_dev *i2c_dev)
> >>  	i2c_writel(i2c_dev, 0x0, I2C_TLOW_SEXT);
> >>  }
> >>  
> >> +static int tegra_i2c_poll_register(struct tegra_i2c_dev *i2c_dev,
> >> +				   u32 reg, u32 mask, u32 delay_us,
> >> +				   u32 timeout_us)
> >> +{
> >> +	void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg);
> >> +	u32 val;
> >> +
> >> +	if (!i2c_dev->is_curr_atomic_xfer)
> >> +		return readl_relaxed_poll_timeout(addr, val, !(val & mask),
> >> +						  delay_us, timeout_us);
> >> +
> >> +	return readl_relaxed_poll_timeout_atomic(addr, val, !(val & mask),
> >> +						 delay_us, timeout_us);
> >> +}
> >> +
> >>  static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
> >>  {
> >> -	u32 mask, val, offset, reg_offset;
> >> -	void __iomem *addr;
> >> +	u32 mask, val, offset;
> >>  	int err;
> >>  
> >>  	if (i2c_dev->hw->has_mst_fifo) {
> >> @@ -534,16 +548,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
> >>  	val |= mask;
> >>  	i2c_writel(i2c_dev, val, offset);
> >>  
> >> -	reg_offset = tegra_i2c_reg_addr(i2c_dev, offset);
> >> -	addr = i2c_dev->base + reg_offset;
> >> -
> >> -	if (i2c_dev->is_curr_atomic_xfer)
> >> -		err = readl_relaxed_poll_timeout_atomic(addr, val, !(val & mask),
> >> -							1000, 1000000);
> >> -	else
> >> -		err = readl_relaxed_poll_timeout(addr, val, !(val & mask),
> >> -						 1000, 1000000);
> >> -
> >> +	err = tegra_i2c_poll_register(i2c_dev, offset, mask, 1000, 1000000);
> >>  	if (err) {
> >>  		dev_err(i2c_dev->dev, "failed to flush FIFO\n");
> >>  		return err;
> >> @@ -553,30 +558,18 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
> >>  
> >>  static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
> >>  {
> >> -	unsigned long reg_offset;
> >> -	void __iomem *addr;
> >> -	u32 val;
> >>  	int err;
> >>  
> >> -	if (i2c_dev->hw->has_config_load_reg) {
> >> -		reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_CONFIG_LOAD);
> >> -		addr = i2c_dev->base + reg_offset;
> >> -		i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
> >> +	if (!i2c_dev->hw->has_config_load_reg)
> >> +		return 0;
> >>  
> >> -		if (i2c_dev->is_curr_atomic_xfer)
> >> -			err = readl_relaxed_poll_timeout_atomic(
> >> -						addr, val, val == 0, 1000,
> >> -						I2C_CONFIG_LOAD_TIMEOUT);
> >> -		else
> >> -			err = readl_relaxed_poll_timeout(
> >> -						addr, val, val == 0, 1000,
> >> -						I2C_CONFIG_LOAD_TIMEOUT);
> >> +	i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
> >>  
> >> -		if (err) {
> >> -			dev_warn(i2c_dev->dev,
> >> -				 "timeout waiting for config load\n");
> >> -			return err;
> >> -		}
> >> +	err = tegra_i2c_poll_register(i2c_dev, I2C_CONFIG_LOAD, 0xffffffff,
> >> +				      1000, I2C_CONFIG_LOAD_TIMEOUT);
> >> +	if (err) {
> >> +		dev_warn(i2c_dev->dev, "timeout waiting for config load\n");
> >> +		return err;
> >>  	}
> > 
> > The deindentation in this hunk is messing up the diffstat in my opinion.
> > It would probably be worth splitting that into a separate patch to make
> > it more evident that this patch actually removes boilerplate.
> 
> This is intentional and it's mentioned in the v7 changelog.
> 
> Previously there was another patch that did what you're suggesting, but
> Andy Shevchenko objected that it was causing a "ping-pong" code changes
> where one patch did a change and then next patch changes the changed
> code again.

Hm... alright then:

Reviewed-by: Thierry Reding <treding@...dia.com>

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)