Il 15/04/22 08:14, Hsin-Yi Wang ha scritto:
On Fri, Apr 15, 2022 at 1:59 PM Rex-BC Chen <rex-bc.chen@xxxxxxxxxxxx> wrote:
To prevent infinite loop when tracking voltage, we calculate the maximum
value for each platform data.
We assume min voltage is 0 and tracking target voltage using
min_volt_shift for each iteration.
The retry_max is 3 times of expeted iteration count.
Signed-off-by: Rex-BC Chen <rex-bc.chen@xxxxxxxxxxxx>
I'm sorry Rex, but this commit has to be squashed with 09/15, as the logic is
that each commit has to be acceptable, and 09/15 is not, without this fix.
Besides, as Hsin-Yi suggested, calculating this every time may hit performance,
but at the same time I don't want to lose this explicit calculation...
---
drivers/cpufreq/mediatek-cpufreq.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index cc44a7a9427a..d4c00237e862 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -86,6 +86,16 @@ static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,
struct regulator *proc_reg = info->proc_reg;
struct regulator *sram_reg = info->sram_reg;
int pre_vproc, pre_vsram, new_vsram, vsram, vproc, ret;
+ int retry_max;
+
+ /*
+ * We assume min voltage is 0 and tracking target voltage using
+ * min_volt_shift for each iteration.
+ * The retry_max is 3 times of expeted iteration count.
+ */
+ retry_max = 3 * DIV_ROUND_UP(max(info->soc_data->sram_max_volt,
+ info->soc_data->proc_max_volt),
+ info->soc_data->min_volt_shift);
mtk_cpufreq_voltage_tracking() will be called very frequently.
retry_max is the same every time mtk_cpufreq_voltage_tracking() is
called. Is it better to calculate before and store in
mtk_cpu_dvfs_info?
...so I agree with this solution: perhaps you can add a "vtrack_max" variable to
mtk_cpu_dvfs_info as suggested, and fill in that one in function
mtk_cpu_dvfs_info_init(), where we effectively initialize all-the-things.
Cheers,
Angelo
