All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sangbeom Kim <sbkim73@samsung.com>
To: "'Samuel Ortiz'" <sameo@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
Subject: RE: [PATCH 2/3] mfd: Add initial S5M8751 support
Date: Tue, 05 Jul 2011 08:49:14 +0900	[thread overview]
Message-ID: <035b01cc3aa4$fb4fa490$f1eeedb0$@com> (raw)
In-Reply-To: <20110704140731.GC3021@sortiz-mobl>

Hi,
Thanks for your kindly comment.

On Monday, July 04, 2011 11:08 PM +0900, Samuel Ortiz wrote:
> On Wed, Jun 22, 2011 at 02:53:56PM +0900, Sangbeom Kim wrote:
> > +#define SLEEPB_ENABLE		1
> > +#define SLEEPB_DISABLE		0
> > +
> > +static DEFINE_MUTEX(io_mutex);
> I would prefer to see your IO mutex defined from your s5m8751 structure.

Ok, I will make IO mutex in s5m8751 structure in the next version.
> 
> > +int s5m8751_clear_bits(struct s5m8751 *s5m8751, uint8_t reg, uint8_t
> mask)
> > +{
> > +	uint8_t reg_val;
> > +	int ret = 0;
> > +
> > +	ret = s5m8751_reg_read(s5m8751, reg, &reg_val);
> > +	if (ret)
> > +		return ret;
> > +
> > +	reg_val &= ~mask;
> > +	ret = s5m8751_reg_write(s5m8751, reg, reg_val);
> > +
> > +	return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(s5m8751_clear_bits);
> > +
> > +int s5m8751_set_bits(struct s5m8751 *s5m8751, uint8_t reg, uint8_t
mask)
> > +{
> > +	uint8_t reg_val;
> > +	int ret = 0;
> > +
> > +	ret = s5m8751_reg_read(s5m8751, reg, &reg_val);
> > +	if (ret)
> > +		return ret;
> > +
> > +	reg_val |= mask;
> > +	ret = s5m8751_reg_write(s5m8751, reg, reg_val);
> > +
> > +	return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(s5m8751_set_bits);
> Your locking for both of those routines is also racy. There's nothing
> preventing a writre to happen between your read and your write. They need
> to
> happen atomically, and for that you need to take the lonk in the clear/set
> bits routine.
Ok, I will add mutex_lock between read and write in the next version.
Sooner or later, I will submit new patches.

Thanks,
SB Kim


  reply	other threads:[~2011-07-04 23:49 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-22  5:53 [PATCH 0/3] S5M8751 core driver Sangbeom Kim
2011-06-22  5:53 ` [PATCH 1/3] mfd: Add S5M8751 register definitions Sangbeom Kim
2011-06-22 12:42   ` Mark Brown
2011-06-22 23:59     ` Sangbeom Kim
2011-06-22  5:53 ` [PATCH 2/3] mfd: Add initial S5M8751 support Sangbeom Kim
2011-06-22 12:48   ` Mark Brown
2011-06-23  1:14     ` Sangbeom Kim
2011-07-04 14:07   ` Samuel Ortiz
2011-07-04 23:49     ` Sangbeom Kim [this message]
2011-06-22  5:53 ` [PATCH 3/3] mfd: Add I2C control support for S5M8751 Sangbeom Kim
2011-06-22  8:56   ` Maxin B John
2011-06-22 12:50   ` Mark Brown
2011-06-23  1:25     ` Sangbeom Kim
2011-06-23  1:28       ` Mark Brown
2011-06-23  2:21         ` Sangbeom Kim
2011-06-23 10:35           ` Mark Brown

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='035b01cc3aa4$fb4fa490$f1eeedb0$@com' \
    --to=sbkim73@samsung.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=sameo@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.