linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Marcus Wolf <marcus.wolf@smarthome-wolf.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Subject: Re: staging: pi433: Possible bug in rf69.c
Date: Fri, 10 Nov 2017 22:32:59 +0300	[thread overview]
Message-ID: <20171110193258.qv6dbokqpjrrq3yb@mwanda> (raw)
In-Reply-To: <709d3e3f-be3b-aa98-1cf6-6a048ef14d7b@smarthome-wolf.de>

On Fri, Nov 10, 2017 at 06:23:32PM +0100, Marcus Wolf wrote:
> Hi everybody!
> 
> Just comparing the master of Gregs statging of pi433 with my local SVN
> to review all changes, that were done the last monthes.
> 
> I am not sure, but maybe we imported a bug in rf69.c lines 378 and
> following:
> 
> Gregs repo:
> 	case automatic:	 return WRITE_REG(REG_LNA, ( (READ_REG(REG_LNA) & ~MASK_LNA_GAIN) & LNA_GAIN_AUTO) );
> my repo:
> 	case automatic:	 return WRITE_REG(REG_LNA, ( (READ_REG(REG_LNA) & ~MASK_LNA_GAIN) | LNA_GAIN_AUTO) );

I edited the lines for clarity.  The difference is that your repo does
a bitwise OR "| LNA_GAIN_AUTO" and the kernel.org code does a bitwise
"& LNA_GAIN_AUTO".

The kernel repo hasn't changed since you sent us the driver in commit
874bcba65f9a ('staging: pi433: New driver').  I agree that & doesn't
seem to make sense and I'm disapointed that it doesn't cause a Smatch
warning.

But LNA_GAIN_AUTO is zero so maybe | BIT(LNA_GAIN_AUTO) was intended
instead of | LNA_GAIN_AUTO.  I don't know...  No one on this list knows
the answer probably.  :/

regards,
dan caprenter

  reply	other threads:[~2017-11-10 19:33 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-10 17:23 staging: pi433: Possible bug in rf69.c Marcus Wolf
2017-11-10 19:32 ` Dan Carpenter [this message]
2017-11-11  7:55   ` Marcus Wolf
2017-11-11  8:40     ` Dan Carpenter
2017-11-11  8:45     ` Dan Carpenter
2017-11-11  9:42       ` Marcus Wolf
2017-11-11 11:18         ` Greg Kroah-Hartman
2017-11-11 11:42           ` Marcus Wolf
2017-11-11 11:49             ` Greg Kroah-Hartman
2017-11-11 11:51               ` Marcus Wolf
2017-11-11 12:33                 ` Greg Kroah-Hartman
2017-11-11 12:10         ` Dan Carpenter
2017-11-11 16:02 ` Joe Perches
2017-11-11 16:40   ` Marcus Wolf

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=20171110193258.qv6dbokqpjrrq3yb@mwanda \
    --to=dan.carpenter@oracle.com \
    --cc=devel@driverdev.osuosl.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=marcus.wolf@smarthome-wolf.de \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).