Re: [PATCH v2 1/4] drm/amdgpu/mst: Stop ignoring error codes and deadlocking
From: Lyude Paul
Date: Fri Nov 18 2022 - 14:54:42 EST
JFYI - I'm not sure of the correct commit ID to add for the Fixes: tag since
it's in your branch, so I'll omit that and let you add it into the patch
On Fri, 2022-11-18 at 14:47 -0500, Lyude Paul wrote:
> of course, will do in just a moment
>
> On Fri, 2022-11-18 at 14:46 -0500, Alex Deucher wrote:
> > I've already picked this up. Can you send a follow up patch with just
> > the coverity fix?
> >
> > Alex
> >
> > On Fri, Nov 18, 2022 at 2:17 PM Lyude Paul <lyude@xxxxxxxxxx> wrote:
> > >
> > > JFYI, Coverity pointed out one more issue with this series so I'm going to
> > > send out a respin real quick to fix it. It's just a missing variable
> > > assignment (we leave ret unassigned by mistake in
> > > pre_compute_mst_dsc_configs()) so I will carry over your r-b on it.
> > >
> > > On Wed, 2022-11-16 at 04:39 +0000, Lin, Wayne wrote:
> > > > [Public]
> > > >
> > > > All the patch set looks good to me. Feel free to add:
> > > > Reviewed-by: Wayne Lin <Wayne.Lin@xxxxxxx>
> > > >
> > > > Again, thank you Lyude for helping on this!!!
> > > >
> > > > Regards,
> > > > Wayne
> > > > > -----Original Message-----
> > > > > From: Lyude Paul <lyude@xxxxxxxxxx>
> > > > > Sent: Tuesday, November 15, 2022 6:18 AM
> > > > > To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> > > > > Cc: Wentland, Harry <Harry.Wentland@xxxxxxx>; stable@xxxxxxxxxxxxxxx;
> > > > > Li, Sun peng (Leo) <Sunpeng.Li@xxxxxxx>; Siqueira, Rodrigo
> > > > > <Rodrigo.Siqueira@xxxxxxx>; Deucher, Alexander
> > > > > <Alexander.Deucher@xxxxxxx>; Koenig, Christian
> > > > > <Christian.Koenig@xxxxxxx>; Pan, Xinhui <Xinhui.Pan@xxxxxxx>; David
> > > > > Airlie <airlied@xxxxxxxxx>; Daniel Vetter <daniel@xxxxxxxx>; Kazlauskas,
> > > > > Nicholas <Nicholas.Kazlauskas@xxxxxxx>; Pillai, Aurabindo
> > > > > <Aurabindo.Pillai@xxxxxxx>; Li, Roman <Roman.Li@xxxxxxx>; Zuo, Jerry
> > > > > <Jerry.Zuo@xxxxxxx>; Wu, Hersen <hersenxs.wu@xxxxxxx>; Lin, Wayne
> > > > > <Wayne.Lin@xxxxxxx>; Thomas Zimmermann <tzimmermann@xxxxxxx>;
> > > > > Mahfooz, Hamza <Hamza.Mahfooz@xxxxxxx>; Hung, Alex
> > > > > <Alex.Hung@xxxxxxx>; Mikita Lipski <mikita.lipski@xxxxxxx>; Liu,
> > > > > Wenjing <Wenjing.Liu@xxxxxxx>; Francis, David
> > > > > <David.Francis@xxxxxxx>; open list:DRM DRIVERS <dri-
> > > > > devel@xxxxxxxxxxxxxxxxxxxxx>; open list <linux-kernel@xxxxxxxxxxxxxxx>
> > > > > Subject: [PATCH v2 1/4] drm/amdgpu/mst: Stop ignoring error codes and
> > > > > deadlocking
> > > > >
> > > > > It appears that amdgpu makes the mistake of completely ignoring the return
> > > > > values from the DP MST helpers, and instead just returns a simple true/false.
> > > > > In this case, it seems to have come back to bite us because as a result of
> > > > > simply returning false from compute_mst_dsc_configs_for_state(), amdgpu
> > > > > had no way of telling when a deadlock happened from these helpers. This
> > > > > could definitely result in some kernel splats.
> > > > >
> > > > > V2:
> > > > > * Address Wayne's comments (fix another bunch of spots where we weren't
> > > > > passing down return codes)
> > > > >
> > > > > Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
> > > > > Fixes: 8c20a1ed9b4f ("drm/amd/display: MST DSC compute fair share")
> > > > > Cc: Harry Wentland <harry.wentland@xxxxxxx>
> > > > > Cc: <stable@xxxxxxxxxxxxxxx> # v5.6+
> > > > > ---
> > > > > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 18 +-
> > > > > .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 235 ++++++++++------
> > > > > --
> > > > > .../display/amdgpu_dm/amdgpu_dm_mst_types.h | 12 +-
> > > > > 3 files changed, 147 insertions(+), 118 deletions(-)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > > > > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > > > > index 0db2a88cd4d7b..852a2100c6b38 100644
> > > > > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > > > > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > > > > @@ -6462,7 +6462,7 @@ static int
> > > > > dm_update_mst_vcpi_slots_for_dsc(struct drm_atomic_state *state,
> > > > > struct drm_connector_state *new_con_state;
> > > > > struct amdgpu_dm_connector *aconnector;
> > > > > struct dm_connector_state *dm_conn_state;
> > > > > - int i, j;
> > > > > + int i, j, ret;
> > > > > int vcpi, pbn_div, pbn, slot_num = 0;
> > > > >
> > > > > for_each_new_connector_in_state(state, connector,
> > > > > new_con_state, i) { @@ -6509,8 +6509,11 @@ static int
> > > > > dm_update_mst_vcpi_slots_for_dsc(struct drm_atomic_state *state,
> > > > > dm_conn_state->pbn = pbn;
> > > > > dm_conn_state->vcpi_slots = slot_num;
> > > > >
> > > > > - drm_dp_mst_atomic_enable_dsc(state, aconnector-
> > > > > > port, dm_conn_state->pbn,
> > > > > - false);
> > > > > + ret = drm_dp_mst_atomic_enable_dsc(state,
> > > > > aconnector->port,
> > > > > + dm_conn_state-
> > > > > > pbn, false);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > +
> > > > > continue;
> > > > > }
> > > > >
> > > > > @@ -9523,10 +9526,9 @@ static int amdgpu_dm_atomic_check(struct
> > > > > drm_device *dev,
> > > > >
> > > > > #if defined(CONFIG_DRM_AMD_DC_DCN)
> > > > > if (dc_resource_is_dsc_encoding_supported(dc)) {
> > > > > - if (!pre_validate_dsc(state, &dm_state, vars)) {
> > > > > - ret = -EINVAL;
> > > > > + ret = pre_validate_dsc(state, &dm_state, vars);
> > > > > + if (ret != 0)
> > > > > goto fail;
> > > > > - }
> > > > > }
> > > > > #endif
> > > > >
> > > > > @@ -9621,9 +9623,9 @@ static int amdgpu_dm_atomic_check(struct
> > > > > drm_device *dev,
> > > > > }
> > > > >
> > > > > #if defined(CONFIG_DRM_AMD_DC_DCN)
> > > > > - if (!compute_mst_dsc_configs_for_state(state, dm_state-
> > > > > > context, vars)) {
> > > > > + ret = compute_mst_dsc_configs_for_state(state, dm_state-
> > > > > > context, vars);
> > > > > + if (ret) {
> > > > >
> > > > > DRM_DEBUG_DRIVER("compute_mst_dsc_configs_for_state()
> > > > > failed\n");
> > > > > - ret = -EINVAL;
> > > > > goto fail;
> > > > > }
> > > > >
> > > > > diff --git
> > > > > a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> > > > > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> > > > > index 6ff96b4bdda5c..bba2e8aaa2c20 100644
> > > > > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> > > > > +++
> > > > > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> > > > > @@ -703,13 +703,13 @@ static int bpp_x16_from_pbn(struct
> > > > > dsc_mst_fairness_params param, int pbn)
> > > > > return dsc_config.bits_per_pixel;
> > > > > }
> > > > >
> > > > > -static bool increase_dsc_bpp(struct drm_atomic_state *state,
> > > > > - struct drm_dp_mst_topology_state *mst_state,
> > > > > - struct dc_link *dc_link,
> > > > > - struct dsc_mst_fairness_params *params,
> > > > > - struct dsc_mst_fairness_vars *vars,
> > > > > - int count,
> > > > > - int k)
> > > > > +static int increase_dsc_bpp(struct drm_atomic_state *state,
> > > > > + struct drm_dp_mst_topology_state *mst_state,
> > > > > + struct dc_link *dc_link,
> > > > > + struct dsc_mst_fairness_params *params,
> > > > > + struct dsc_mst_fairness_vars *vars,
> > > > > + int count,
> > > > > + int k)
> > > > > {
> > > > > int i;
> > > > > bool bpp_increased[MAX_PIPES];
> > > > > @@ -719,6 +719,7 @@ static bool increase_dsc_bpp(struct
> > > > > drm_atomic_state *state,
> > > > > int remaining_to_increase = 0;
> > > > > int link_timeslots_used;
> > > > > int fair_pbn_alloc;
> > > > > + int ret = 0;
> > > > >
> > > > > for (i = 0; i < count; i++) {
> > > > > if (vars[i + k].dsc_enabled) {
> > > > > @@ -757,52 +758,60 @@ static bool increase_dsc_bpp(struct
> > > > > drm_atomic_state *state,
> > > > >
> > > > > if (initial_slack[next_index] > fair_pbn_alloc) {
> > > > > vars[next_index].pbn += fair_pbn_alloc;
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > -
> > > > > params[next_index].port->mgr,
> > > > > -
> > > > > params[next_index].port,
> > > > > -
> > > > > vars[next_index].pbn) < 0)
> > > > > - return false;
> > > > > - if (!drm_dp_mst_atomic_check(state)) {
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > +
> > > > > params[next_index].port->mgr,
> > > > > +
> > > > > params[next_index].port,
> > > > > +
> > > > > vars[next_index].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > +
> > > > > + ret = drm_dp_mst_atomic_check(state);
> > > > > + if (ret == 0) {
> > > > > vars[next_index].bpp_x16 =
> > > > > bpp_x16_from_pbn(params[next_index], vars[next_index].pbn);
> > > > > } else {
> > > > > vars[next_index].pbn -= fair_pbn_alloc;
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > -
> > > > > params[next_index].port->mgr,
> > > > > -
> > > > > params[next_index].port,
> > > > > -
> > > > > vars[next_index].pbn) < 0)
> > > > > - return false;
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > +
> > > > > params[next_index].port->mgr,
> > > > > +
> > > > > params[next_index].port,
> > > > > +
> > > > > vars[next_index].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > }
> > > > > } else {
> > > > > vars[next_index].pbn += initial_slack[next_index];
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > -
> > > > > params[next_index].port->mgr,
> > > > > -
> > > > > params[next_index].port,
> > > > > -
> > > > > vars[next_index].pbn) < 0)
> > > > > - return false;
> > > > > - if (!drm_dp_mst_atomic_check(state)) {
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > +
> > > > > params[next_index].port->mgr,
> > > > > +
> > > > > params[next_index].port,
> > > > > +
> > > > > vars[next_index].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > +
> > > > > + ret = drm_dp_mst_atomic_check(state);
> > > > > + if (ret == 0) {
> > > > > vars[next_index].bpp_x16 =
> > > > > params[next_index].bw_range.max_target_bpp_x16;
> > > > > } else {
> > > > > vars[next_index].pbn -=
> > > > > initial_slack[next_index];
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > -
> > > > > params[next_index].port->mgr,
> > > > > -
> > > > > params[next_index].port,
> > > > > -
> > > > > vars[next_index].pbn) < 0)
> > > > > - return false;
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > +
> > > > > params[next_index].port->mgr,
> > > > > +
> > > > > params[next_index].port,
> > > > > +
> > > > > vars[next_index].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > }
> > > > > }
> > > > >
> > > > > bpp_increased[next_index] = true;
> > > > > remaining_to_increase--;
> > > > > }
> > > > > - return true;
> > > > > + return 0;
> > > > > }
> > > > >
> > > > > -static bool try_disable_dsc(struct drm_atomic_state *state,
> > > > > - struct dc_link *dc_link,
> > > > > - struct dsc_mst_fairness_params *params,
> > > > > - struct dsc_mst_fairness_vars *vars,
> > > > > - int count,
> > > > > - int k)
> > > > > +static int try_disable_dsc(struct drm_atomic_state *state,
> > > > > + struct dc_link *dc_link,
> > > > > + struct dsc_mst_fairness_params *params,
> > > > > + struct dsc_mst_fairness_vars *vars,
> > > > > + int count,
> > > > > + int k)
> > > > > {
> > > > > int i;
> > > > > bool tried[MAX_PIPES];
> > > > > @@ -810,6 +819,7 @@ static bool try_disable_dsc(struct drm_atomic_state
> > > > > *state,
> > > > > int max_kbps_increase;
> > > > > int next_index;
> > > > > int remaining_to_try = 0;
> > > > > + int ret;
> > > > >
> > > > > for (i = 0; i < count; i++) {
> > > > > if (vars[i + k].dsc_enabled
> > > > > @@ -840,49 +850,52 @@ static bool try_disable_dsc(struct
> > > > > drm_atomic_state *state,
> > > > > break;
> > > > >
> > > > > vars[next_index].pbn =
> > > > > kbps_to_peak_pbn(params[next_index].bw_range.stream_kbps);
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > - params[next_index].port-
> > > > > > mgr,
> > > > > - params[next_index].port,
> > > > > - vars[next_index].pbn) < 0)
> > > > > - return false;
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > + params[next_index].port-
> > > > > > mgr,
> > > > > + params[next_index].port,
> > > > > + vars[next_index].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > >
> > > > > - if (!drm_dp_mst_atomic_check(state)) {
> > > > > + ret = drm_dp_mst_atomic_check(state);
> > > > > + if (ret == 0) {
> > > > > vars[next_index].dsc_enabled = false;
> > > > > vars[next_index].bpp_x16 = 0;
> > > > > } else {
> > > > > vars[next_index].pbn =
> > > > > kbps_to_peak_pbn(params[next_index].bw_range.max_kbps);
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > -
> > > > > params[next_index].port->mgr,
> > > > > -
> > > > > params[next_index].port,
> > > > > -
> > > > > vars[next_index].pbn) < 0)
> > > > > - return false;
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > +
> > > > > params[next_index].port->mgr,
> > > > > +
> > > > > params[next_index].port,
> > > > > +
> > > > > vars[next_index].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > }
> > > > >
> > > > > tried[next_index] = true;
> > > > > remaining_to_try--;
> > > > > }
> > > > > - return true;
> > > > > + return 0;
> > > > > }
> > > > >
> > > > > -static bool compute_mst_dsc_configs_for_link(struct drm_atomic_state
> > > > > *state,
> > > > > - struct dc_state *dc_state,
> > > > > - struct dc_link *dc_link,
> > > > > - struct dsc_mst_fairness_vars *vars,
> > > > > - struct drm_dp_mst_topology_mgr
> > > > > *mgr,
> > > > > - int *link_vars_start_index)
> > > > > +static int compute_mst_dsc_configs_for_link(struct drm_atomic_state
> > > > > *state,
> > > > > + struct dc_state *dc_state,
> > > > > + struct dc_link *dc_link,
> > > > > + struct dsc_mst_fairness_vars *vars,
> > > > > + struct drm_dp_mst_topology_mgr
> > > > > *mgr,
> > > > > + int *link_vars_start_index)
> > > > > {
> > > > > struct dc_stream_state *stream;
> > > > > struct dsc_mst_fairness_params params[MAX_PIPES];
> > > > > struct amdgpu_dm_connector *aconnector;
> > > > > struct drm_dp_mst_topology_state *mst_state =
> > > > > drm_atomic_get_mst_topology_state(state, mgr);
> > > > > int count = 0;
> > > > > - int i, k;
> > > > > + int i, k, ret;
> > > > > bool debugfs_overwrite = false;
> > > > >
> > > > > memset(params, 0, sizeof(params));
> > > > >
> > > > > if (IS_ERR(mst_state))
> > > > > - return false;
> > > > > + return PTR_ERR(mst_state);
> > > > >
> > > > > mst_state->pbn_div = dm_mst_get_pbn_divider(dc_link); #if
> > > > > defined(CONFIG_DRM_AMD_DC_DCN) @@ -933,7 +946,7 @@ static bool
> > > > > compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
> > > > >
> > > > > if (count == 0) {
> > > > > ASSERT(0);
> > > > > - return true;
> > > > > + return 0;
> > > > > }
> > > > >
> > > > > /* k is start index of vars for current phy link used by mst hub */ @@
> > > > > -947,13 +960,17 @@ static bool compute_mst_dsc_configs_for_link(struct
> > > > > drm_atomic_state *state,
> > > > > vars[i + k].pbn =
> > > > > kbps_to_peak_pbn(params[i].bw_range.stream_kbps);
> > > > > vars[i + k].dsc_enabled = false;
> > > > > vars[i + k].bpp_x16 = 0;
> > > > > - if (drm_dp_atomic_find_time_slots(state, params[i].port-
> > > > > > mgr, params[i].port,
> > > > > - vars[i + k].pbn) < 0)
> > > > > - return false;
> > > > > + ret = drm_dp_atomic_find_time_slots(state, params[i].port-
> > > > > > mgr, params[i].port,
> > > > > + vars[i + k].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > }
> > > > > - if (!drm_dp_mst_atomic_check(state) && !debugfs_overwrite) {
> > > > > + ret = drm_dp_mst_atomic_check(state);
> > > > > + if (ret == 0 && !debugfs_overwrite) {
> > > > > set_dsc_configs_from_fairness_vars(params, vars, count, k);
> > > > > - return true;
> > > > > + return 0;
> > > > > + } else if (ret != -ENOSPC) {
> > > > > + return ret;
> > > > > }
> > > > >
> > > > > /* Try max compression */
> > > > > @@ -962,31 +979,36 @@ static bool
> > > > > compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
> > > > > vars[i + k].pbn =
> > > > > kbps_to_peak_pbn(params[i].bw_range.min_kbps);
> > > > > vars[i + k].dsc_enabled = true;
> > > > > vars[i + k].bpp_x16 =
> > > > > params[i].bw_range.min_target_bpp_x16;
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > params[i].port->mgr,
> > > > > - params[i].port, vars[i
> > > > > + k].pbn) < 0)
> > > > > - return false;
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > params[i].port->mgr,
> > > > > + params[i].port,
> > > > > vars[i + k].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > } else {
> > > > > vars[i + k].pbn =
> > > > > kbps_to_peak_pbn(params[i].bw_range.stream_kbps);
> > > > > vars[i + k].dsc_enabled = false;
> > > > > vars[i + k].bpp_x16 = 0;
> > > > > - if (drm_dp_atomic_find_time_slots(state,
> > > > > params[i].port->mgr,
> > > > > - params[i].port, vars[i
> > > > > + k].pbn) < 0)
> > > > > - return false;
> > > > > + ret = drm_dp_atomic_find_time_slots(state,
> > > > > params[i].port->mgr,
> > > > > + params[i].port,
> > > > > vars[i + k].pbn);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > > }
> > > > > }
> > > > > - if (drm_dp_mst_atomic_check(state))
> > > > > - return false;
> > > > > + ret = drm_dp_mst_atomic_check(state);
> > > > > + if (ret != 0)
> > > > > + return ret;
> > > > >
> > > > > /* Optimize degree of compression */
> > > > > - if (!increase_dsc_bpp(state, mst_state, dc_link, params, vars, count,
> > > > > k))
> > > > > - return false;
> > > > > + ret = increase_dsc_bpp(state, mst_state, dc_link, params, vars,
> > > > > count, k);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > >
> > > > > - if (!try_disable_dsc(state, dc_link, params, vars, count, k))
> > > > > - return false;
> > > > > + ret = try_disable_dsc(state, dc_link, params, vars, count, k);
> > > > > + if (ret < 0)
> > > > > + return ret;
> > > > >
> > > > > set_dsc_configs_from_fairness_vars(params, vars, count, k);
> > > > >
> > > > > - return true;
> > > > > + return 0;
> > > > > }
> > > > >
> > > > > static bool is_dsc_need_re_compute(
> > > > > @@ -1087,15 +1109,16 @@ static bool is_dsc_need_re_compute(
> > > > > return is_dsc_need_re_compute;
> > > > > }
> > > > >
> > > > > -bool compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
> > > > > - struct dc_state *dc_state,
> > > > > - struct dsc_mst_fairness_vars *vars)
> > > > > +int compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
> > > > > + struct dc_state *dc_state,
> > > > > + struct dsc_mst_fairness_vars *vars)
> > > > > {
> > > > > int i, j;
> > > > > struct dc_stream_state *stream;
> > > > > bool computed_streams[MAX_PIPES];
> > > > > struct amdgpu_dm_connector *aconnector;
> > > > > int link_vars_start_index = 0;
> > > > > + int ret = 0;
> > > > >
> > > > > for (i = 0; i < dc_state->stream_count; i++)
> > > > > computed_streams[i] = false;
> > > > > @@ -1118,17 +1141,19 @@ bool compute_mst_dsc_configs_for_state(struct
> > > > > drm_atomic_state *state,
> > > > > continue;
> > > > >
> > > > > if (dcn20_remove_stream_from_ctx(stream->ctx->dc,
> > > > > dc_state, stream) != DC_OK)
> > > > > - return false;
> > > > > + return -EINVAL;
> > > > >
> > > > > if (!is_dsc_need_re_compute(state, dc_state, stream->link))
> > > > > continue;
> > > > >
> > > > > mutex_lock(&aconnector->mst_mgr.lock);
> > > > > - if (!compute_mst_dsc_configs_for_link(state, dc_state,
> > > > > stream->link, vars,
> > > > > - &aconnector->mst_mgr,
> > > > > - &link_vars_start_index)) {
> > > > > +
> > > > > + ret = compute_mst_dsc_configs_for_link(state, dc_state,
> > > > > stream->link, vars,
> > > > > + &aconnector->mst_mgr,
> > > > > + &link_vars_start_index);
> > > > > + if (ret != 0) {
> > > > > mutex_unlock(&aconnector->mst_mgr.lock);
> > > > > - return false;
> > > > > + return ret;
> > > > > }
> > > > > mutex_unlock(&aconnector->mst_mgr.lock);
> > > > >
> > > > > @@ -1143,22 +1168,22 @@ bool compute_mst_dsc_configs_for_state(struct
> > > > > drm_atomic_state *state,
> > > > >
> > > > > if (stream->timing.flags.DSC == 1)
> > > > > if (dc_stream_add_dsc_to_resource(stream->ctx-
> > > > > > dc, dc_state, stream) != DC_OK)
> > > > > - return false;
> > > > > + return -EINVAL;
> > > > > }
> > > > >
> > > > > - return true;
> > > > > + return ret;
> > > > > }
> > > > >
> > > > > -static bool
> > > > > - pre_compute_mst_dsc_configs_for_state(struct drm_atomic_state
> > > > > *state,
> > > > > - struct dc_state *dc_state,
> > > > > - struct dsc_mst_fairness_vars
> > > > > *vars)
> > > > > +static int pre_compute_mst_dsc_configs_for_state(struct
> > > > > drm_atomic_state *state,
> > > > > + struct dc_state *dc_state,
> > > > > + struct dsc_mst_fairness_vars
> > > > > *vars)
> > > > > {
> > > > > int i, j;
> > > > > struct dc_stream_state *stream;
> > > > > bool computed_streams[MAX_PIPES];
> > > > > struct amdgpu_dm_connector *aconnector;
> > > > > int link_vars_start_index = 0;
> > > > > + int ret;
> > > > >
> > > > > for (i = 0; i < dc_state->stream_count; i++)
> > > > > computed_streams[i] = false;
> > > > > @@ -1184,11 +1209,12 @@ static bool
> > > > > continue;
> > > > >
> > > > > mutex_lock(&aconnector->mst_mgr.lock);
> > > > > - if (!compute_mst_dsc_configs_for_link(state, dc_state,
> > > > > stream->link, vars,
> > > > > - &aconnector->mst_mgr,
> > > > > - &link_vars_start_index)) {
> > > > > + ret = compute_mst_dsc_configs_for_link(state, dc_state,
> > > > > stream->link, vars,
> > > > > + &aconnector->mst_mgr,
> > > > > + &link_vars_start_index);
> > > > > + if (ret != 0) {
> > > > > mutex_unlock(&aconnector->mst_mgr.lock);
> > > > > - return false;
> > > > > + return ret;
> > > > > }
> > > > > mutex_unlock(&aconnector->mst_mgr.lock);
> > > > >
> > > > > @@ -1198,7 +1224,7 @@ static bool
> > > > > }
> > > > > }
> > > > >
> > > > > - return true;
> > > > > + return ret;
> > > > > }
> > > > >
> > > > > static int find_crtc_index_in_state_by_stream(struct drm_atomic_state
> > > > > *state, @@ -1253,9 +1279,9 @@ static bool
> > > > > is_dsc_precompute_needed(struct drm_atomic_state *state)
> > > > > return ret;
> > > > > }
> > > > >
> > > > > -bool pre_validate_dsc(struct drm_atomic_state *state,
> > > > > - struct dm_atomic_state **dm_state_ptr,
> > > > > - struct dsc_mst_fairness_vars *vars)
> > > > > +int pre_validate_dsc(struct drm_atomic_state *state,
> > > > > + struct dm_atomic_state **dm_state_ptr,
> > > > > + struct dsc_mst_fairness_vars *vars)
> > > > > {
> > > > > int i;
> > > > > struct dm_atomic_state *dm_state;
> > > > > @@ -1264,11 +1290,12 @@ bool pre_validate_dsc(struct drm_atomic_state
> > > > > *state,
> > > > >
> > > > > if (!is_dsc_precompute_needed(state)) {
> > > > > DRM_INFO_ONCE("DSC precompute is not needed.\n");
> > > > > - return true;
> > > > > + return 0;
> > > > > }
> > > > > - if (dm_atomic_get_state(state, dm_state_ptr)) {
> > > > > + ret = dm_atomic_get_state(state, dm_state_ptr);
> > > > > + if (ret != 0) {
> > > > > DRM_INFO_ONCE("dm_atomic_get_state() failed\n");
> > > > > - return false;
> > > > > + return ret;
> > > > > }
> > > > > dm_state = *dm_state_ptr;
> > > > >
> > > > > @@ -1280,7 +1307,7 @@ bool pre_validate_dsc(struct drm_atomic_state
> > > > > *state,
> > > > >
> > > > > local_dc_state = kmemdup(dm_state->context, sizeof(struct
> > > > > dc_state), GFP_KERNEL);
> > > > > if (!local_dc_state)
> > > > > - return false;
> > > > > + return -ENOMEM;
> > > > >
> > > > > for (i = 0; i < local_dc_state->stream_count; i++) {
> > > > > struct dc_stream_state *stream = dm_state->context-
> > > > > > streams[i]; @@ -1316,9 +1343,9 @@ bool pre_validate_dsc(struct
> > > > > drm_atomic_state *state,
> > > > > if (ret != 0)
> > > > > goto clean_exit;
> > > > >
> > > > > - if (!pre_compute_mst_dsc_configs_for_state(state, local_dc_state,
> > > > > vars)) {
> > > > > + ret = pre_compute_mst_dsc_configs_for_state(state, local_dc_state,
> > > > > vars);
> > > > > + if (ret != 0) {
> > > > >
> > > > > DRM_INFO_ONCE("pre_compute_mst_dsc_configs_for_state()
> > > > > failed\n");
> > > > > - ret = -EINVAL;
> > > > > goto clean_exit;
> > > > > }
> > > > >
> > > > > @@ -1349,7 +1376,7 @@ bool pre_validate_dsc(struct drm_atomic_state
> > > > > *state,
> > > > >
> > > > > kfree(local_dc_state);
> > > > >
> > > > > - return (ret == 0);
> > > > > + return ret;
> > > > > }
> > > > >
> > > > > static unsigned int kbps_from_pbn(unsigned int pbn) diff --git
> > > > > a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
> > > > > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
> > > > > index b92a7c5671aa2..97fd70df531bf 100644
> > > > > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
> > > > > +++
> > > > > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
> > > > > @@ -53,15 +53,15 @@ struct dsc_mst_fairness_vars {
> > > > > struct amdgpu_dm_connector *aconnector; };
> > > > >
> > > > > -bool compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
> > > > > - struct dc_state *dc_state,
> > > > > - struct dsc_mst_fairness_vars *vars);
> > > > > +int compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
> > > > > + struct dc_state *dc_state,
> > > > > + struct dsc_mst_fairness_vars *vars);
> > > > >
> > > > > bool needs_dsc_aux_workaround(struct dc_link *link);
> > > > >
> > > > > -bool pre_validate_dsc(struct drm_atomic_state *state,
> > > > > - struct dm_atomic_state **dm_state_ptr,
> > > > > - struct dsc_mst_fairness_vars *vars);
> > > > > +int pre_validate_dsc(struct drm_atomic_state *state,
> > > > > + struct dm_atomic_state **dm_state_ptr,
> > > > > + struct dsc_mst_fairness_vars *vars);
> > > > >
> > > > > enum dc_status dm_dp_mst_is_port_support_mode(
> > > > > struct amdgpu_dm_connector *aconnector,
> > > > > --
> > > > > 2.37.3
> > > >
> > >
> > > --
> > > Cheers,
> > > Lyude Paul (she/her)
> > > Software Engineer at Red Hat
> > >
> >
>
--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat