diff options
| author | Jon Mayo <jmayo@nvidia.com> | 2011-05-13 17:28:58 -0700 |
|---|---|---|
| committer | Varun Colbert <vcolbert@nvidia.com> | 2011-05-17 11:53:35 -0700 |
| commit | 263e4e4ec418dd3e76925c49ac314425159d3d63 (patch) | |
| tree | b8be9857c848e96e3852f2ace8c4ab9efb4788c1 /drivers | |
| parent | e1e2a385c8015a8d7ef1ee8d79421a7a3bff129c (diff) | |
ARM: tegra: dc: lower hdmi clock before set rate
choose a higher clock divider on hdmi before switching clock parents.
This prevents hdmi from exceeding its DVFS clock limits.
Change-Id: I09c23498bf6450cf19e91accb788715582c3befb
Reviewed-on: http://git-master/r/31605
Reviewed-by: Scott Williams <scwilliams@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
Reviewed-by: Jonathan Mayo <jmayo@nvidia.com>
Tested-by: Jonathan Mayo <jmayo@nvidia.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/video/tegra/dc/hdmi.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/video/tegra/dc/hdmi.c b/drivers/video/tegra/dc/hdmi.c index bda63c28800f..f1ca9fafbef8 100644 --- a/drivers/video/tegra/dc/hdmi.c +++ b/drivers/video/tegra/dc/hdmi.c @@ -1326,6 +1326,7 @@ static void tegra_dc_hdmi_enable(struct tegra_dc *dc) int err; unsigned long val; unsigned i; + unsigned long oldrate; /* enbale power, clocks, resets, etc. */ @@ -1335,6 +1336,11 @@ static void tegra_dc_hdmi_enable(struct tegra_dc *dc) */ clk_enable(hdmi->disp1_clk); clk_enable(hdmi->disp2_clk); + + /* back off multiplier before attaching to parent at new rate. */ + oldrate = clk_get_rate(hdmi->clk); + clk_set_rate(hdmi->clk, oldrate / 2); + tegra_dc_setup_clk(dc, hdmi->clk); clk_set_rate(hdmi->clk, dc->mode.pclk); |