| Message ID | 20171221112411.21550-1-net147@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Thu, Dec 21, 2017 at 10:24:11PM +1100, Jonathan Liu wrote: > There are several issues in sun4i_tmds_determine_rate: > - doesn't check if the best match was already set before comparing it > with the enumerated parameters which could result in integer divide > by zero > - doesn't consider rate halving when determining closest match if it > can't match the requested rate exactly > - sets best_div to i which corresponds to rate halving when it should be > set to j which corresponds to the divider > > Fix these issues. > > Fixes: 9c5681011a0c ("drm/sun4i: Add HDMI support") > Signed-off-by: Jonathan Liu <net147@gmail.com> Please make separate patches for each of these issues, if possible detailing how do you reproduce them. Maxime
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c index dc332ea56f6c..3ecffa52c814 100644 --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c @@ -102,10 +102,13 @@ static int sun4i_tmds_determine_rate(struct clk_hw *hw, goto out; } - if (abs(rate - rounded / i) < - abs(rate - best_parent / best_div)) { + if (!best_parent || + abs(rate - rounded / i / j) < + abs(rate - best_parent / best_half / + best_div)) { best_parent = rounded; - best_div = i; + best_half = i; + best_div = j; } } }
There are several issues in sun4i_tmds_determine_rate: - doesn't check if the best match was already set before comparing it with the enumerated parameters which could result in integer divide by zero - doesn't consider rate halving when determining closest match if it can't match the requested rate exactly - sets best_div to i which corresponds to rate halving when it should be set to j which corresponds to the divider Fix these issues. Fixes: 9c5681011a0c ("drm/sun4i: Add HDMI support") Signed-off-by: Jonathan Liu <net147@gmail.com> --- drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)