[PATCH v1 4/5] PM / devfreq: tegra30: Use clk_round_rate_unboundly()

From: Dmitry Osipenko
Date: Mon Mar 30 2020 - 19:20:19 EST


The clk_round_rate() doesn't work for us properly if clock rate is bounded
by a min/max rate that is requested by some other clk-user because we're
building devfreq's OPP table based on the rounding.

In particular this becomes a problem if display driver is probed earlier
than devfreq, and thus, display adds a memory bandwidth request using
interconnect API, which results in a minimum clock-rate being set for
the memory clk. In a result, the lowest devfreq OPP rate is getting
limited to the minimum rate imposed by the display driver.

Let's use new clk_round_rate_unboundly() that resolves the problem by
rounding clock rate without taking into account min/max limits imposed by
active clk users.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
drivers/devfreq/tegra30-devfreq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index 28b2c7ca416e..34f6291e880c 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -834,7 +834,7 @@ static int tegra_devfreq_probe(struct platform_device *pdev)

reset_control_deassert(tegra->reset);

- rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
+ rate = clk_round_rate_unboundly(tegra->emc_clock, ULONG_MAX);
if (rate < 0) {
dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
return rate;
@@ -849,7 +849,7 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
}

for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
- rate = clk_round_rate(tegra->emc_clock, rate);
+ rate = clk_round_rate_unboundly(tegra->emc_clock, rate);

if (rate < 0) {
dev_err(&pdev->dev,
--
2.25.1