diff options
| author | Jonathan Liu <net147@gmail.com> | 2018-01-09 13:03:21 +1100 |
|---|---|---|
| committer | Maxime Ripard <maxime.ripard@free-electrons.com> | 2018-01-11 13:25:13 +0100 |
| commit | 111f4c3309397370f1fd9579754f06b82055041d (patch) | |
| tree | 8896804504831fcbd831e47344016e929ab61456 /drivers/gpu/drm/sun4i | |
| parent | b0bb222440a5c8273f67dd37946707e6ba6ad832 (diff) | |
drm/sun4i: hdmi: Check for unset best_parent in sun4i_tmds_determine_rate
It is possible that if there is no exact rate match and
"rounded = clk_hw_round_rate(parent, ideal)" gives high enough values
(e.g. if rounded is 2 * ideal) that the condition
"abs(rate - rounded / i) < abs(rate - best_parent / best_div)" is never
met and best_parent is never set. This results in req->rate and
req->best_parent_rate being assigned 0.
To avoid this, we set best_parent to the first calculated rate if it is
unset. The sun4i_tmds_calc_divider function already has a similar check.
Fixes: 9c5681011a0c ("drm/sun4i: Add HDMI support")
Signed-off-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180109020323.11852-2-net147@gmail.com
Diffstat (limited to 'drivers/gpu/drm/sun4i')
| -rw-r--r-- | drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c index dc332ea56f6c..4d235e5ea31c 100644 --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c @@ -102,7 +102,7 @@ static int sun4i_tmds_determine_rate(struct clk_hw *hw, goto out; } - if (abs(rate - rounded / i) < + if (!best_parent || abs(rate - rounded / i) < abs(rate - best_parent / best_div)) { best_parent = rounded; best_div = i; |