On Sun, Apr 23, 2017 at 7:33 PM, Mario Kleiner <mario.kleiner.de at gmail.com> wrote: > At dot clocks > approx. 250 Mhz, some of these calcs will overflow and > cause miscalculation of latency watermarks, and for some overflows also > divide-by-zero driver crash. Make calcs more overflow resistant. > > This is a direct port of the corresponding patch from amdgpu-kms, > copy-paste for cik from dce-8 and si from dce-6, with a slightly > simpler variant for evergreen dce-4/5. > > Only tested on DCE-4 evergreen with a Radeon HD-5770. > > Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com> > Cc: Alex Deucher <alexander.deucher at amd.com> Applied the series. thanks! Alex > --- > drivers/gpu/drm/radeon/cik.c | 19 +++---------------- > drivers/gpu/drm/radeon/evergreen.c | 8 +------- > drivers/gpu/drm/radeon/si.c | 19 +++---------------- > 3 files changed, 7 insertions(+), 39 deletions(-) > > diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c > index 53710dd..4f034cb 100644 > --- a/drivers/gpu/drm/radeon/cik.c > +++ b/drivers/gpu/drm/radeon/cik.c > @@ -9150,23 +9150,10 @@ static u32 dce8_latency_watermark(struct dce8_wm_params *wm) > a.full = dfixed_const(available_bandwidth); > b.full = dfixed_const(wm->num_heads); > a.full = dfixed_div(a, b); > + tmp = div_u64((u64) dmif_size * (u64) wm->disp_clk, mc_latency + 512); > + tmp = min(dfixed_trunc(a), tmp); > > - b.full = dfixed_const(mc_latency + 512); > - c.full = dfixed_const(wm->disp_clk); > - b.full = dfixed_div(b, c); > - > - c.full = dfixed_const(dmif_size); > - b.full = dfixed_div(c, b); > - > - tmp = min(dfixed_trunc(a), dfixed_trunc(b)); > - > - b.full = dfixed_const(1000); > - c.full = dfixed_const(wm->disp_clk); > - b.full = dfixed_div(c, b); > - c.full = dfixed_const(wm->bytes_per_pixel); > - b.full = dfixed_mul(b, c); > - > - lb_fill_bw = min(tmp, dfixed_trunc(b)); > + lb_fill_bw = min(tmp, wm->disp_clk * wm->bytes_per_pixel / 1000); > > a.full = dfixed_const(max_src_lines_per_dst_line * wm->src_width * wm->bytes_per_pixel); > b.full = dfixed_const(1000); > diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c > index d1b1e0c..3c9c133 100644 > --- a/drivers/gpu/drm/radeon/evergreen.c > +++ b/drivers/gpu/drm/radeon/evergreen.c > @@ -2188,13 +2188,7 @@ static u32 evergreen_latency_watermark(struct evergreen_wm_params *wm) > b.full = dfixed_const(wm->num_heads); > a.full = dfixed_div(a, b); > > - b.full = dfixed_const(1000); > - c.full = dfixed_const(wm->disp_clk); > - b.full = dfixed_div(c, b); > - c.full = dfixed_const(wm->bytes_per_pixel); > - b.full = dfixed_mul(b, c); > - > - lb_fill_bw = min(dfixed_trunc(a), dfixed_trunc(b)); > + lb_fill_bw = min(dfixed_trunc(a), wm->disp_clk * wm->bytes_per_pixel / 1000); > > a.full = dfixed_const(max_src_lines_per_dst_line * wm->src_width * wm->bytes_per_pixel); > b.full = dfixed_const(1000); > diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c > index 528e5a4..3efdfd0 100644 > --- a/drivers/gpu/drm/radeon/si.c > +++ b/drivers/gpu/drm/radeon/si.c > @@ -2204,23 +2204,10 @@ static u32 dce6_latency_watermark(struct dce6_wm_params *wm) > a.full = dfixed_const(available_bandwidth); > b.full = dfixed_const(wm->num_heads); > a.full = dfixed_div(a, b); > + tmp = div_u64((u64) dmif_size * (u64) wm->disp_clk, mc_latency + 512); > + tmp = min(dfixed_trunc(a), tmp); > > - b.full = dfixed_const(mc_latency + 512); > - c.full = dfixed_const(wm->disp_clk); > - b.full = dfixed_div(b, c); > - > - c.full = dfixed_const(dmif_size); > - b.full = dfixed_div(c, b); > - > - tmp = min(dfixed_trunc(a), dfixed_trunc(b)); > - > - b.full = dfixed_const(1000); > - c.full = dfixed_const(wm->disp_clk); > - b.full = dfixed_div(c, b); > - c.full = dfixed_const(wm->bytes_per_pixel); > - b.full = dfixed_mul(b, c); > - > - lb_fill_bw = min(tmp, dfixed_trunc(b)); > + lb_fill_bw = min(tmp, wm->disp_clk * wm->bytes_per_pixel / 1000); > > a.full = dfixed_const(max_src_lines_per_dst_line * wm->src_width * wm->bytes_per_pixel); > b.full = dfixed_const(1000); > -- > 2.7.4 > > _______________________________________________ > dri-devel mailing list > dri-devel at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
