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authorKevin Hilman <khilman@ti.com>2012-10-03 02:39:03 +0400
committerKevin Hilman <khilman@ti.com>2012-10-09 01:57:34 +0400
commit8df0a6637767474989022b93230a8615f11fb53b (patch)
tree78b455c21370f4625a5b6c75cede4404413973b3
parent16642a2e7be23bbda013fc32d8f6c68982eab603 (diff)
downloadlinux-8df0a6637767474989022b93230a8615f11fb53b.tar.xz
cpufreq: OMAP: ensure valid clock rate before scaling
Ensure the clock rate that will be used is a valid one before attempting to scale the voltage. Currently the driver assumes it has a valid frequency from the OPP table, but boards using different system oscillators might not have exact matches with the OPP table, and result in a failing call to clk_set_rate(). This is particularily bad because the voltage may be scaled even though the frequency is not. This will obviously lead to some unpredictable behavior, especially if the frequency is high and the voltage is dropped. Thanks to Joni Lapilainen for reporting crashes seen on 3430/n900. Reported-by: Joni Lapilainen <joni.lapilainen@gmail.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Kevin Hilman <khilman@ti.com>
-rw-r--r--drivers/cpufreq/omap-cpufreq.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 65f8e9a54975..0fe395aea114 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -108,6 +108,14 @@ static int omap_target(struct cpufreq_policy *policy,
}
freq = freqs.new * 1000;
+ ret = clk_round_rate(mpu_clk, freq);
+ if (IS_ERR_VALUE(ret)) {
+ dev_warn(mpu_dev,
+ "CPUfreq: Cannot find matching frequency for %lu\n",
+ freq);
+ return ret;
+ }
+ freq = ret;
if (mpu_reg) {
opp = opp_find_freq_ceil(mpu_dev, &freq);