linux-kernel - Re: [PATCH 1/4] mfd: smsc: Add support for smsc gpio io/keypad driver

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:	Tue, 21 Aug 2012 17:09:24 +0300
From:	Felipe Balbi <balbi@...com>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc:	Felipe Balbi <balbi@...com>, Sourav Poddar <sourav.poddar@...com>,
	devicetree-discuss@...ts.ozlabs.org,
	linux-arm-kernel@...ts.infradead.org, linux-omap@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-input@...r.kernel.org
Subject: Re: [PATCH 1/4] mfd: smsc: Add support for smsc gpio io/keypad driver

Hi,

On Tue, Aug 21, 2012 at 03:08:03PM +0100, Mark Brown wrote:
> On Tue, Aug 21, 2012 at 04:52:41PM +0300, Felipe Balbi wrote:
> 
> > Fair enough, we have "quiet", but I'm not sure that's enough argument to
> > allow any simple driver to start poluting dmesg with whatever random
> > messages.
> 
> I think if the driver is just logging to say "I'm running" that's noise
> and I do push back on that routinely myself; if the driver is providing
> information it's discovered from the running system then that seems much
> more useful and we should have a sensible way of getting that out in a
> place where users are likely to find.

fair enough. But look at the messages which that driver is printing:

+       regmap_read(smsc->regmap, SMSC_DEV_ID, &ret);
+       dev_dbg(&i2c->dev, "SMSC Device ID: %d\n", ret);
+
+       regmap_read(smsc->regmap, SMSC_DEV_REV, &ret);
+       dev_dbg(&i2c->dev, "SMSC Device ID: %d\n", ret);
+
+       regmap_read(smsc->regmap, SMSC_VEN_ID_L, &ret);
+       dev_dbg(&i2c->dev, "SMSC Device ID: %d\n", ret);
+
+       regmap_read(smsc->regmap, SMSC_VEN_ID_H, &ret);
+       dev_dbg(&i2c->dev, "SMSC Device ID: %d\n", ret);

You can't possibly understand what that'll print. First of all, VEN_ID_H
and VEN_ID_L should be ORed together. Second, the user will see the same
message four times in a row, with different values, but see that driver
claims that all four values refer to the device id. What this should do,
is at least combine all four messages into a single one of the format:

dev_(dbg|info)(&i2c->dev, "SMSCxxx devid: %02x rev: %02x venid: %02x\n",
	devid, rev, (venid_h << 8) | venid_l);

or something similar.

-- 
balbi

Download attachment "signature.asc" of type "application/pgp-signature" (837 bytes)