From: Axel Lin <axel.lin@ingics.com>
Date: Tue, 5 Aug 2014 02:08:31 +0000 (+0800)
Subject: hwmon: (lm92) Prevent overflow problem when writing large limits
X-Git-Tag: v3.2.64~181
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b2d64341dab783119bc1e27b48aba99738bd93e8;p=pandora-kernel.git

hwmon: (lm92) Prevent overflow problem when writing large limits

commit 5b963089161b8fb244889c972edf553b9d737545 upstream.

On platforms with sizeof(int) < sizeof(long), writing a temperature
limit larger than MAXINT will result in unpredictable limit values
written to the chip. Avoid auto-conversion from long to int to fix
the problem.

The hysteresis temperature range depends on the value of
data->temp[attr->index], since val is subtracted from it.
Use a wider clamp, [-120000, 220000] should do to cover the
possible range. Also add missing TEMP_TO_REG() on writes into
cached hysteresis value.

Also uses clamp_val to simplify the code a bit.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
[Guenter Roeck: Fixed double TEMP_TO_REG on hysteresis updates]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[bwh: Backported to 3.2:
 - s/temp\[attr->index\]/temp1_crit/
 - s/temp\[t_hyst\]/temp1_hyst/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

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