| Message ID | 20170724173311.27170-4-sebastian.reichel@collabora.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 24/07/17 20:33, Sebastian Reichel wrote: > This is a workaround for a hardware bug occuring on OMAP3 > with manually updated panels. Details about the HW bug are > unknown to me, but without this fix the panel refresh does > not work at all on Nokia N950. > > Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> > --- > drivers/gpu/drm/omapdrm/dss/dispc.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c > index fd7504b37e3b..b6dca5ee34d4 100644 > --- a/drivers/gpu/drm/omapdrm/dss/dispc.c > +++ b/drivers/gpu/drm/omapdrm/dss/dispc.c > @@ -1398,6 +1398,18 @@ void dispc_ovl_compute_fifo_thresholds(enum omap_plane_id plane, > } > } > > +void dispc_ovl_set_manual_fifo_threshold(enum omap_plane_id plane) > +{ > + u32 fifo_low, fifo_high; > + bool use_fifo_merge = false; > + bool use_manual_update = true; > + > + dispc_ovl_compute_fifo_thresholds(plane, &fifo_low, &fifo_high, > + use_fifo_merge, use_manual_update); > + > + dispc_ovl_set_fifo_threshold(plane, fifo_low, fifo_high); > +} > + > static void dispc_ovl_set_mflag(enum omap_plane_id plane, bool enable) > { > int bit; > @@ -2566,6 +2578,10 @@ static int dispc_ovl_setup(enum omap_plane_id plane, > oi->zorder, oi->pre_mult_alpha, oi->global_alpha, > oi->rotation_type, replication, vm, mem_to_mem); > > + /* manual mode needs other fifo thresholds */ > + if (mgr_fld_read(channel, DISPC_MGR_FLD_STALLMODE)) > + dispc_ovl_set_manual_fifo_threshold(plane); > + > return r; > } We don't have the stallmode for all channels. And on OMAP2 it's for RFBI, and I don't know if that needs different thresholds or not. Also, I'm not sure if OMAP4-5 DSI needs this. And I think it's good to mention the unknown bug in the comment too. And yes, it's unknown to me too, I never figured it out. These thresholds just seemed to work, while the default did not. So I think we need to check that the platform is OMAP3 and channel is LCD. We can later extend that to cover OMAP4-5 if needed. Tomi
Hi Tomi, On Fri, Dec 01, 2017 at 02:10:42PM +0200, Tomi Valkeinen wrote: > > On 24/07/17 20:33, Sebastian Reichel wrote: > > This is a workaround for a hardware bug occuring on OMAP3 > > with manually updated panels. Details about the HW bug are > > unknown to me, but without this fix the panel refresh does > > not work at all on Nokia N950. > > > > Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> > > --- > > drivers/gpu/drm/omapdrm/dss/dispc.c | 16 ++++++++++++++++ > > 1 file changed, 16 insertions(+) > > > > diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c > > index fd7504b37e3b..b6dca5ee34d4 100644 > > --- a/drivers/gpu/drm/omapdrm/dss/dispc.c > > +++ b/drivers/gpu/drm/omapdrm/dss/dispc.c > > @@ -1398,6 +1398,18 @@ void dispc_ovl_compute_fifo_thresholds(enum omap_plane_id plane, > > } > > } > > > > +void dispc_ovl_set_manual_fifo_threshold(enum omap_plane_id plane) > > +{ > > + u32 fifo_low, fifo_high; > > + bool use_fifo_merge = false; > > + bool use_manual_update = true; > > + > > + dispc_ovl_compute_fifo_thresholds(plane, &fifo_low, &fifo_high, > > + use_fifo_merge, use_manual_update); > > + > > + dispc_ovl_set_fifo_threshold(plane, fifo_low, fifo_high); > > +} > > + > > static void dispc_ovl_set_mflag(enum omap_plane_id plane, bool enable) > > { > > int bit; > > @@ -2566,6 +2578,10 @@ static int dispc_ovl_setup(enum omap_plane_id plane, > > oi->zorder, oi->pre_mult_alpha, oi->global_alpha, > > oi->rotation_type, replication, vm, mem_to_mem); > > > > + /* manual mode needs other fifo thresholds */ > > + if (mgr_fld_read(channel, DISPC_MGR_FLD_STALLMODE)) > > + dispc_ovl_set_manual_fifo_threshold(plane); > > + > > return r; > > } > > We don't have the stallmode for all channels. And on OMAP2 it's for > RFBI, and I don't know if that needs different thresholds or not. Also, > I'm not sure if OMAP4-5 DSI needs this. And I think it's good to mention > the unknown bug in the comment too. And yes, it's unknown to me too, I > never figured it out. These thresholds just seemed to work, while the > default did not. > > So I think we need to check that the platform is OMAP3 and channel is > LCD. We can later extend that to cover OMAP4-5 if needed. Ok. I will have a look at this later today. FWIW I test this patchset with OMAP3 (N950) and OMAP4 (Droid 4). OMAP4 works without this patch, but also with the changed thresholds. -- Sebastian
diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c index fd7504b37e3b..b6dca5ee34d4 100644 --- a/drivers/gpu/drm/omapdrm/dss/dispc.c +++ b/drivers/gpu/drm/omapdrm/dss/dispc.c @@ -1398,6 +1398,18 @@ void dispc_ovl_compute_fifo_thresholds(enum omap_plane_id plane, } } +void dispc_ovl_set_manual_fifo_threshold(enum omap_plane_id plane) +{ + u32 fifo_low, fifo_high; + bool use_fifo_merge = false; + bool use_manual_update = true; + + dispc_ovl_compute_fifo_thresholds(plane, &fifo_low, &fifo_high, + use_fifo_merge, use_manual_update); + + dispc_ovl_set_fifo_threshold(plane, fifo_low, fifo_high); +} + static void dispc_ovl_set_mflag(enum omap_plane_id plane, bool enable) { int bit; @@ -2566,6 +2578,10 @@ static int dispc_ovl_setup(enum omap_plane_id plane, oi->zorder, oi->pre_mult_alpha, oi->global_alpha, oi->rotation_type, replication, vm, mem_to_mem); + /* manual mode needs other fifo thresholds */ + if (mgr_fld_read(channel, DISPC_MGR_FLD_STALLMODE)) + dispc_ovl_set_manual_fifo_threshold(plane); + return r; }
This is a workaround for a hardware bug occuring on OMAP3 with manually updated panels. Details about the HW bug are unknown to me, but without this fix the panel refresh does not work at all on Nokia N950. Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> --- drivers/gpu/drm/omapdrm/dss/dispc.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)