From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
If a reader of the ring buffer is doing a poll, and waiting for the ring
buffer to hit a specific watermark, there could be a case where it gets
into an infinite ping-pong loop.
The poll code has:
rbwork->full_waiters_pending = true;
if (!cpu_buffer->shortest_full ||
cpu_buffer->shortest_full > full)
cpu_buffer->shortest_full = full;
The writer will see full_waiters_pending and check if the ring buffer is
filled over the percentage of the shortest_full value. If it is, it calls
an irq_work to wake up all the waiters.
But the code could get into a circular loop:
CPU 0 CPU 1
----- -----
[ Poll ]
[ shortest_full = 0 ]
rbwork->full_waiters_pending = true;
if (rbwork->full_waiters_pending &&
[ buffer percent ] > shortest_full) {
rbwork->wakeup_full = true;
[ queue_irqwork ]
cpu_buffer->shortest_full = full;
[ IRQ work ]
if (rbwork->wakeup_full) {
cpu_buffer->shortest_full = 0;
wakeup poll waiters;
[woken]
if ([ buffer percent ] > full)
break;
rbwork->full_waiters_pending = true;
if (rbwork->full_waiters_pending &&
[ buffer percent ] > shortest_full) {
rbwork->wakeup_full = true;
[ queue_irqwork ]
cpu_buffer->shortest_full = full;
[ IRQ work ]
if (rbwork->wakeup_full) {
cpu_buffer->shortest_full = 0;
wakeup poll waiters;
[woken]
[ Wash, rinse, repeat! ]
In the poll, the shortest_full needs to be set before the
full_pending_waiters, as once that is set, the writer will compare the
current shortest_full (which is incorrect) to decide to call the irq_work,
which will reset the shortest_full (expecting the readers to update it).
Also move the setting of full_waiters_pending after the check if the ring
buffer has the required percentage filled. There's no reason to tell the
writer to wake up waiters if there are no waiters.
Cc: stable(a)vger.kernel.org
Fixes: 42fb0a1e84ff5 ("tracing/ring-buffer: Have polling block on watermark")
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/ring_buffer.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index aa332ace108b..adfe603a769b 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -964,16 +964,32 @@ __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
poll_wait(filp, &rbwork->full_waiters, poll_table);
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
- rbwork->full_waiters_pending = true;
if (!cpu_buffer->shortest_full ||
cpu_buffer->shortest_full > full)
cpu_buffer->shortest_full = full;
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
- } else {
- poll_wait(filp, &rbwork->waiters, poll_table);
- rbwork->waiters_pending = true;
+ if (full_hit(buffer, cpu, full))
+ return EPOLLIN | EPOLLRDNORM;
+ /*
+ * Only allow full_waiters_pending update to be seen after
+ * the shortest_full is set. If the writer sees the
+ * full_waiters_pending flag set, it will compare the
+ * amount in the ring buffer to shortest_full. If the amount
+ * in the ring buffer is greater than the shortest_full
+ * percent, it will call the irq_work handler to wake up
+ * this list. The irq_handler will reset shortest_full
+ * back to zero. That's done under the reader_lock, but
+ * the below smp_mb() makes sure that the update to
+ * full_waiters_pending doesn't leak up into the above.
+ */
+ smp_mb();
+ rbwork->full_waiters_pending = true;
+ return 0;
}
+ poll_wait(filp, &rbwork->waiters, poll_table);
+ rbwork->waiters_pending = true;
+
/*
* There's a tight race between setting the waiters_pending and
* checking if the ring buffer is empty. Once the waiters_pending bit
@@ -989,9 +1005,6 @@ __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
*/
smp_mb();
- if (full)
- return full_hit(buffer, cpu, full) ? EPOLLIN | EPOLLRDNORM : 0;
-
if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) ||
(cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))
return EPOLLIN | EPOLLRDNORM;
--
2.43.0
The PD of Type-C port needs to be updated in pd_set. Unlink the Type-C
port device to the old PD before linking it to a new one.
Fixes: cd099cde4ed2 ("usb: typec: tcpm: Support multiple capabilities")
Cc: stable(a)vger.kernel.org
Signed-off-by: Kyle Tso <kyletso(a)google.com>
---
drivers/usb/typec/tcpm/tcpm.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 3d505614bff1..896f594b9328 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -6907,7 +6907,9 @@ static int tcpm_pd_set(struct typec_port *p, struct usb_power_delivery *pd)
port->port_source_caps = data->source_cap;
port->port_sink_caps = data->sink_cap;
+ typec_port_set_usb_power_delivery(p, NULL);
port->selected_pd = pd;
+ typec_port_set_usb_power_delivery(p, port->selected_pd);
unlock:
mutex_unlock(&port->lock);
return ret;
--
2.44.0.278.ge034bb2e1d-goog
From: Wenjing Liu <wenjing.liu(a)amd.com>
[why]
During minimal transition commit, the base state could be freed if it is current state.
This is because after committing minimal transition state, the current state will be
swapped to the minimal transition state and the old current state will be released.
the release could cause the old current state's memory to be freed. However dc
will derefernce this memory when release minimal transition state. Therefore, we
need to retain the old current state until we release minimal transition state.
Cc: Mario Limonciello <mario.limonciello(a)amd.com>
Cc: Alex Deucher <alexander.deucher(a)amd.com>
Cc: stable(a)vger.kernel.org
Reviewed-by: Josip Pavic <josip.pavic(a)amd.com>
Acked-by: Wayne Lin <wayne.lin(a)amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu(a)amd.com>
---
drivers/gpu/drm/amd/display/dc/core/dc.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index a372c4965adf..ab0c920333be 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -4203,7 +4203,6 @@ static void release_minimal_transition_state(struct dc *dc,
{
restore_minimal_pipe_split_policy(dc, base_context, policy);
dc_state_release(minimal_transition_context);
- /* restore previous pipe split and odm policy */
}
static void force_vsync_flip_in_minimal_transition_context(struct dc_state *context)
@@ -4258,7 +4257,7 @@ static bool is_pipe_topology_transition_seamless_with_intermediate_step(
intermediate_state, final_state);
}
-static void swap_and_free_current_context(struct dc *dc,
+static void swap_and_release_current_context(struct dc *dc,
struct dc_state *new_context, struct dc_stream_state *stream)
{
@@ -4321,7 +4320,7 @@ static bool commit_minimal_transition_based_on_new_context(struct dc *dc,
commit_planes_for_stream(dc, srf_updates,
surface_count, stream, NULL,
UPDATE_TYPE_FULL, intermediate_context);
- swap_and_free_current_context(
+ swap_and_release_current_context(
dc, intermediate_context, stream);
dc_state_retain(dc->current_state);
success = true;
@@ -4338,6 +4337,7 @@ static bool commit_minimal_transition_based_on_current_context(struct dc *dc,
bool success = false;
struct pipe_split_policy_backup policy;
struct dc_state *intermediate_context;
+ struct dc_state *old_current_state = dc->current_state;
struct dc_surface_update srf_updates[MAX_SURFACE_NUM];
int surface_count;
@@ -4353,8 +4353,10 @@ static bool commit_minimal_transition_based_on_current_context(struct dc *dc,
* with the current state.
*/
restore_planes_and_stream_state(&dc->scratch.current_state, stream);
+ dc_state_retain(old_current_state);
intermediate_context = create_minimal_transition_state(dc,
- dc->current_state, &policy);
+ old_current_state, &policy);
+
if (intermediate_context) {
if (is_pipe_topology_transition_seamless_with_intermediate_step(
dc,
@@ -4367,14 +4369,15 @@ static bool commit_minimal_transition_based_on_current_context(struct dc *dc,
commit_planes_for_stream(dc, srf_updates,
surface_count, stream, NULL,
UPDATE_TYPE_FULL, intermediate_context);
- swap_and_free_current_context(
+ swap_and_release_current_context(
dc, intermediate_context, stream);
dc_state_retain(dc->current_state);
success = true;
}
release_minimal_transition_state(dc, intermediate_context,
- dc->current_state, &policy);
+ old_current_state, &policy);
}
+ dc_state_release(old_current_state);
/*
* Restore stream and plane states back to the values associated with
* new context.
@@ -4496,12 +4499,14 @@ static bool commit_minimal_transition_state(struct dc *dc,
dc->debug.pipe_split_policy != MPC_SPLIT_AVOID ? "MPC in Use" :
"Unknown");
+ dc_state_retain(transition_base_context);
transition_context = create_minimal_transition_state(dc,
transition_base_context, &policy);
if (transition_context) {
ret = dc_commit_state_no_check(dc, transition_context);
release_minimal_transition_state(dc, transition_context, transition_base_context, &policy);
}
+ dc_state_release(transition_base_context);
if (ret != DC_OK) {
/* this should never happen */
@@ -4839,7 +4844,7 @@ static bool update_planes_and_stream_v2(struct dc *dc,
context);
}
if (dc->current_state != context)
- swap_and_free_current_context(dc, context, stream);
+ swap_and_release_current_context(dc, context, stream);
return true;
}
@@ -4941,7 +4946,7 @@ static bool update_planes_and_stream_v3(struct dc *dc,
commit_planes_and_stream_update_with_new_context(dc,
srf_updates, surface_count, stream,
stream_update, update_type, new_context);
- swap_and_free_current_context(dc, new_context, stream);
+ swap_and_release_current_context(dc, new_context, stream);
}
return true;
--
2.37.3
From: Chris Park <chris.park(a)amd.com>
[Why]
Disabling stream encoder invokes a function that no longer exists
in bring-up.
[How]
Check if the function declaration is NULL in disable stream encoder.
Cc: Mario Limonciello <mario.limonciello(a)amd.com>
Cc: Alex Deucher <alexander.deucher(a)amd.com>
Cc: stable(a)vger.kernel.org
Reviewed-by: Charlene Liu <charlene.liu(a)amd.com>
Acked-by: Wayne Lin <wayne.lin(a)amd.com>
Signed-off-by: Chris Park <chris.park(a)amd.com>
---
drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
index 9d5df4c0da59..0ba1feaf96c0 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
@@ -1185,7 +1185,8 @@ void dce110_disable_stream(struct pipe_ctx *pipe_ctx)
if (dccg) {
dccg->funcs->disable_symclk32_se(dccg, dp_hpo_inst);
dccg->funcs->set_dpstreamclk(dccg, REFCLK, tg->inst, dp_hpo_inst);
- dccg->funcs->set_dtbclk_dto(dccg, &dto_params);
+ if (dccg && dccg->funcs->set_dtbclk_dto)
+ dccg->funcs->set_dtbclk_dto(dccg, &dto_params);
}
} else if (dccg && dccg->funcs->disable_symclk_se) {
dccg->funcs->disable_symclk_se(dccg, stream_enc->stream_enc_inst,
--
2.37.3
From: Wenjing Liu <wenjing.liu(a)amd.com>
This reverts commit 6cf00f4c4d5c ("drm/amd/display: Remove pixle rate
limit for subvp")
[why]
The original commit causes a regression when subvp is applied
on ODM required 8k60hz timing. The display shows black screen
on boot. The issue can be recovered with hotplug. It also causes
MPO to fail. We will temprarily revert this commit and investigate
the root cause further.
Cc: Mario Limonciello <mario.limonciello(a)amd.com>
Cc: Alex Deucher <alexander.deucher(a)amd.com>
Cc: stable(a)vger.kernel.org
Reviewed-by: Chaitanya Dhere <chaitanya.dhere(a)amd.com>
Reviewed-by: Martin Leung <martin.leung(a)amd.com>
Acked-by: Wayne Lin <wayne.lin(a)amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu(a)amd.com>
---
drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c
index b49e1dc9d8ba..a0a65e099104 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c
@@ -623,6 +623,7 @@ static bool dcn32_assign_subvp_pipe(struct dc *dc,
* - Not TMZ surface
*/
if (pipe->plane_state && !pipe->top_pipe && !dcn32_is_center_timing(pipe) &&
+ !(pipe->stream->timing.pix_clk_100hz / 10000 > DCN3_2_MAX_SUBVP_PIXEL_RATE_MHZ) &&
(!dcn32_is_psr_capable(pipe) || (context->stream_count == 1 && dc->caps.dmub_caps.subvp_psr)) &&
dc_state_get_pipe_subvp_type(context, pipe) == SUBVP_NONE &&
(refresh_rate < 120 || dcn32_allow_subvp_high_refresh_rate(dc, context, pipe)) &&
--
2.37.3