From 237ede16ba5bcd4d6c612ea280518c48ca31986c Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Tue, 29 Apr 2014 00:24:27 +0530 Subject: cpufreq: powernow-k6: Fix incorrect comparison with max_multipler The value of 'max_multiplier' is meant to be used for comparison with clock_ratio[index].driver_data, not the index itself! Fix the code in powernow_k6_cpu_exit() that has this bug. Also, while at it, make the for-loop condition look for CPUFREQ_TABLE_END, instead of hard-coding the loop count to 8. Reported-by: Viresh Kumar Signed-off-by: Srivatsa S. Bhat Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/powernow-k6.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/cpufreq/powernow-k6.c') diff --git a/drivers/cpufreq/powernow-k6.c b/drivers/cpufreq/powernow-k6.c index 49f120e1bc7b..695a68cfdcd4 100644 --- a/drivers/cpufreq/powernow-k6.c +++ b/drivers/cpufreq/powernow-k6.c @@ -227,8 +227,9 @@ have_busfreq: static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) { unsigned int i; - for (i = 0; i < 8; i++) { - if (i == max_multiplier) + + for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { + if (clock_ratio[i].driver_data == max_multiplier) powernow_k6_target(policy, i); } return 0; -- cgit v1.2.3 From 3221e55b72359c44ed75afbcf707710af5bc2d59 Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Tue, 29 Apr 2014 00:24:42 +0530 Subject: cpufreq: powernow-k6: Fix double invocation of cpufreq_freq_transition_begin/end During frequency transitions, the cpufreq core takes the responsibility of invoking cpufreq_freq_transition_begin() and cpufreq_freq_transition_end() for those cpufreq drivers that define the ->target_index callback but don't set the ASYNC_NOTIFICATION flag. The powernow-k6 cpufreq driver falls under this category, but this driver was invoking the _begin() and _end() APIs itself around frequency transitions, which led to double invocation of the _begin() API. The _begin API makes contending callers wait until the previous invocation is complete. Hence, the powernow-k6 driver ended up waiting on itself, leading to system hangs during boot. Fix this by removing the calls to the _begin() and _end() APIs from the powernow-k6 driver, since they rightly belong to the cpufreq core. (Note that during ->exit(), the powernow-k6 driver sets the frequency without any help from the cpufreq core. So add explicit calls to the _begin() and _end() APIs around that frequency transition alone, to take care of that special case. Also, add a missing 'break' statement there.) Fixes: 12478cf0c55e (cpufreq: Make sure frequency transitions are serialized) Signed-off-by: Srivatsa S. Bhat Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/powernow-k6.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'drivers/cpufreq/powernow-k6.c') diff --git a/drivers/cpufreq/powernow-k6.c b/drivers/cpufreq/powernow-k6.c index 695a68cfdcd4..78904e6ca4a0 100644 --- a/drivers/cpufreq/powernow-k6.c +++ b/drivers/cpufreq/powernow-k6.c @@ -138,22 +138,14 @@ static void powernow_k6_set_cpu_multiplier(unsigned int best_i) static int powernow_k6_target(struct cpufreq_policy *policy, unsigned int best_i) { - struct cpufreq_freqs freqs; if (clock_ratio[best_i].driver_data > max_multiplier) { printk(KERN_ERR PFX "invalid target frequency\n"); return -EINVAL; } - freqs.old = busfreq * powernow_k6_get_cpu_multiplier(); - freqs.new = busfreq * clock_ratio[best_i].driver_data; - - cpufreq_freq_transition_begin(policy, &freqs); - powernow_k6_set_cpu_multiplier(best_i); - cpufreq_freq_transition_end(policy, &freqs, 0); - return 0; } @@ -229,8 +221,18 @@ static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) unsigned int i; for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { - if (clock_ratio[i].driver_data == max_multiplier) + if (clock_ratio[i].driver_data == max_multiplier) { + struct cpufreq_freqs freqs; + + freqs.old = policy->cur; + freqs.new = clock_ratio[i].frequency; + freqs.flags = 0; + + cpufreq_freq_transition_begin(policy, &freqs); powernow_k6_target(policy, i); + cpufreq_freq_transition_end(policy, &freqs, 0); + break; + } } return 0; } -- cgit v1.2.3