Since we need to be able to allow DPMS on->off prop changes after an MST
port has disappeared from the system, we need to be able to make sure we
can compute a config for the resulting atomic commit. Currently this is
impossible when the port has disappeared, since the VCPI slot searching
we try to do in intel_dp_mst_compute_config() will fail with -EINVAL.
Since the only commits we want to allow on no-longer-present MST ports
are ones that shut off display hardware, we already know that no VCPI
allocations are needed. So, hardcode the VCPI slot count to 0 when
intel_dp_mst_compute_config() is called on an MST port that's gone.
Changes since V4:
- Don't use mst_port_gone at all, just check whether or not the drm
connector is registered - Daniel Vetter
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/i915/intel_dp_mst.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index aa21742d8634..0f14c0d1669c 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -38,11 +38,11 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
struct intel_digital_port *intel_dig_port = intel_mst->primary;
struct intel_dp *intel_dp = &intel_dig_port->dp;
- struct intel_connector *connector =
- to_intel_connector(conn_state->connector);
+ struct drm_connector *connector = conn_state->connector;
+ void *port = to_intel_connector(connector)->port;
struct drm_atomic_state *state = pipe_config->base.state;
int bpp;
- int lane_count, slots;
+ int lane_count, slots = 0;
const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
int mst_pbn;
bool constant_n = drm_dp_has_quirk(&intel_dp->desc,
@@ -70,17 +70,23 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
pipe_config->port_clock = intel_dp_max_link_rate(intel_dp);
- if (drm_dp_mst_port_has_audio(&intel_dp->mst_mgr, connector->port))
+ if (drm_dp_mst_port_has_audio(&intel_dp->mst_mgr, port))
pipe_config->has_audio = true;
mst_pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock, bpp);
pipe_config->pbn = mst_pbn;
- slots = drm_dp_atomic_find_vcpi_slots(state, &intel_dp->mst_mgr,
- connector->port, mst_pbn);
- if (slots < 0) {
- DRM_DEBUG_KMS("failed finding vcpi slots:%d\n", slots);
- return false;
+ /* Zombie connectors can't have VCPI slots */
+ if (READ_ONCE(connector->registered)) {
+ slots = drm_dp_atomic_find_vcpi_slots(state,
+ &intel_dp->mst_mgr,
+ port,
+ mst_pbn);
+ if (slots < 0) {
+ DRM_DEBUG_KMS("failed finding vcpi slots:%d\n",
+ slots);
+ return false;
+ }
}
intel_link_compute_m_n(bpp, lane_count,
--
2.17.1
Currently we set intel_connector->mst_port to NULL to signify that the
MST port has been removed from the system so that we can prevent further
action on the port such as connector probes, mode probing, etc.
However, we're going to need access to intel_connector->mst_port in
order to fixup ->best_encoder() so that it can always return the correct
encoder for an MST port to prevent legacy DPMS prop changes from
failing. This should be safe, so instead keep intel_connector->mst_port
always set and instead just check the status of
drm_connector->regustered to signify whether or not the connector has
disappeared from the system.
Changes since v2:
- Add a comment to mst_port_gone (Jani Nikula)
- Change mst_port_gone to a u8 instead of a bool, per the kernel bot.
Apparently bool is discouraged in structs these days
Changes since v4:
- Don't use mst_port_gone at all! Just check if the connector is
registered or not - Daniel Vetter
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/i915/intel_dp_mst.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 43db2e9ac575..aa21742d8634 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -307,9 +307,8 @@ static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector)
struct edid *edid;
int ret;
- if (!intel_dp) {
+ if (!READ_ONCE(connector->registered))
return intel_connector_update_modes(connector, NULL);
- }
edid = drm_dp_mst_get_edid(connector, &intel_dp->mst_mgr, intel_connector->port);
ret = intel_connector_update_modes(connector, edid);
@@ -324,9 +323,10 @@ intel_dp_mst_detect(struct drm_connector *connector, bool force)
struct intel_connector *intel_connector = to_intel_connector(connector);
struct intel_dp *intel_dp = intel_connector->mst_port;
- if (!intel_dp)
+ if (!READ_ONCE(connector->registered))
return connector_status_disconnected;
- return drm_dp_mst_detect_port(connector, &intel_dp->mst_mgr, intel_connector->port);
+ return drm_dp_mst_detect_port(connector, &intel_dp->mst_mgr,
+ intel_connector->port);
}
static void
@@ -366,7 +366,7 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,
int bpp = 24; /* MST uses fixed bpp */
int max_rate, mode_rate, max_lanes, max_link_clock;
- if (!intel_dp)
+ if (!READ_ONCE(connector->registered))
return MODE_ERROR;
if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
@@ -398,7 +398,7 @@ static struct drm_encoder *intel_mst_atomic_best_encoder(struct drm_connector *c
struct intel_dp *intel_dp = intel_connector->mst_port;
struct intel_crtc *crtc = to_intel_crtc(state->crtc);
- if (!intel_dp)
+ if (!READ_ONCE(connector->registered))
return NULL;
return &intel_dp->mst_encoders[crtc->pipe]->base.base;
}
@@ -499,7 +499,6 @@ static void intel_dp_register_mst_connector(struct drm_connector *connector)
static void intel_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
struct drm_connector *connector)
{
- struct intel_connector *intel_connector = to_intel_connector(connector);
struct drm_i915_private *dev_priv = to_i915(connector->dev);
DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, connector->name);
@@ -508,10 +507,6 @@ static void intel_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
if (dev_priv->fbdev)
drm_fb_helper_remove_one_connector(&dev_priv->fbdev->helper,
connector);
- /* prevent race with the check in ->detect */
- drm_modeset_lock(&connector->dev->mode_config.connection_mutex, NULL);
- intel_connector->mst_port = NULL;
- drm_modeset_unlock(&connector->dev->mode_config.connection_mutex);
drm_connector_put(connector);
}
--
2.17.1
As mentioned in the previous commit, we currently prevent new modesets
on recently-removed MST connectors by returning no encoder from our
->best_encoder() callback once the MST port has disappeared. This is
wrong however, because it prevents legacy modesetting users from being
able to disable CRTCs on MST connectors after the connector's respective
topology has disappeared.
So, fix this by instead by just always returning a valid encoder.
Changes since v2:
- Remove usage of atomic MST helper for now, since that got replaced
with a much simpler solution
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/nouveau/dispnv50/disp.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 9f32b10c7c29..31b94bc9ec90 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -843,22 +843,16 @@ nv50_mstc_atomic_best_encoder(struct drm_connector *connector,
{
struct nv50_head *head = nv50_head(connector_state->crtc);
struct nv50_mstc *mstc = nv50_mstc(connector);
- if (mstc->port) {
- struct nv50_mstm *mstm = mstc->mstm;
- return &mstm->msto[head->base.index]->encoder;
- }
- return NULL;
+
+ return &mstc->mstm->msto[head->base.index]->encoder;
}
static struct drm_encoder *
nv50_mstc_best_encoder(struct drm_connector *connector)
{
struct nv50_mstc *mstc = nv50_mstc(connector);
- if (mstc->port) {
- struct nv50_mstm *mstm = mstc->mstm;
- return &mstm->msto[0]->encoder;
- }
- return NULL;
+
+ return &mstc->mstm->msto[0]->encoder;
}
static enum drm_mode_status
--
2.17.1
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 Mon Sep 17 00:00:00 2001
From: Michael Neuling <mikey(a)neuling.org>
Date: Fri, 14 Sep 2018 11:14:11 +1000
Subject: [PATCH] powerpc: Avoid code patching freed init sections
This stops us from doing code patching in init sections after they've
been freed.
In this chain:
kvm_guest_init() ->
kvm_use_magic_page() ->
fault_in_pages_readable() ->
__get_user() ->
__get_user_nocheck() ->
barrier_nospec();
We have a code patching location at barrier_nospec() and
kvm_guest_init() is an init function. This whole chain gets inlined,
so when we free the init section (hence kvm_guest_init()), this code
goes away and hence should no longer be patched.
We seen this as userspace memory corruption when using a memory
checker while doing partition migration testing on powervm (this
starts the code patching post migration via
/sys/kernel/mobility/migration). In theory, it could also happen when
using /sys/kernel/debug/powerpc/barrier_nospec.
Cc: stable(a)vger.kernel.org # 4.13+
Signed-off-by: Michael Neuling <mikey(a)neuling.org>
Reviewed-by: Nicholas Piggin <npiggin(a)gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy(a)c-s.fr>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 1a951b00465d..1fffbba8d6a5 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -9,6 +9,7 @@ extern void ppc_printk_progress(char *s, unsigned short hex);
extern unsigned int rtas_data;
extern unsigned long long memory_limit;
+extern bool init_mem_is_free;
extern unsigned long klimit;
extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask);
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 850f3b8f4da5..6ae2777c220d 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -28,6 +28,12 @@ static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
{
int err;
+ /* Make sure we aren't patching a freed init section */
+ if (init_mem_is_free && init_section_contains(exec_addr, 4)) {
+ pr_debug("Skipping init section patching addr: 0x%px\n", exec_addr);
+ return 0;
+ }
+
__put_user_size(instr, patch_addr, 4, err);
if (err)
return err;
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 5c8530d0c611..04ccb274a620 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -63,6 +63,7 @@
#endif
unsigned long long memory_limit;
+bool init_mem_is_free;
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
@@ -396,6 +397,7 @@ void free_initmem(void)
{
ppc_md.progress = ppc_printk_progress;
mark_initmem_nx();
+ init_mem_is_free = true;
free_initmem_default(POISON_FREE_INITMEM);
}
Currently, i915 appears to rely on blocking modesets on
no-longer-present MSTB ports by simply returning NULL for
->best_encoder(), which in turn causes any new atomic commits that don't
disable the CRTC to fail. This is wrong however, since we still want to
allow userspace to disable CRTCs on no-longer-present MSTB ports by
changing the DPMS state to off and this still requires that we retrieve
an encoder.
So, fix this by always returning a valid encoder regardless of the state
of the MST port.
Changes since v1:
- Remove mst atomic helper, since this got replaced with a much simpler
solution
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/i915/intel_dp_mst.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 0f14c0d1669c..7f155b4f1a7d 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -404,8 +404,6 @@ static struct drm_encoder *intel_mst_atomic_best_encoder(struct drm_connector *c
struct intel_dp *intel_dp = intel_connector->mst_port;
struct intel_crtc *crtc = to_intel_crtc(state->crtc);
- if (!READ_ONCE(connector->registered))
- return NULL;
return &intel_dp->mst_encoders[crtc->pipe]->base.base;
}
--
2.17.1
Since we need to be able to allow DPMS on->off prop changes after an MST
port has disappeared from the system, we need to be able to make sure we
can compute a config for the resulting atomic commit. Currently this is
impossible when the port has disappeared, since the VCPI slot searching
we try to do in intel_dp_mst_compute_config() will fail with -EINVAL.
Since the only commits we want to allow on no-longer-present MST ports
are ones that shut off display hardware, we already know that no VCPI
allocations are needed. So, hardcode the VCPI slot count to 0 when
intel_dp_mst_compute_config() is called on an MST port that's gone.
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
Changes since V4:
- Don't use mst_port_gone at all, just check whether or not the drm
connector is registered - Daniel Vetter
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
---
drivers/gpu/drm/i915/intel_dp_mst.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index aa21742d8634..0f14c0d1669c 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -38,11 +38,11 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
struct intel_digital_port *intel_dig_port = intel_mst->primary;
struct intel_dp *intel_dp = &intel_dig_port->dp;
- struct intel_connector *connector =
- to_intel_connector(conn_state->connector);
+ struct drm_connector *connector = conn_state->connector;
+ void *port = to_intel_connector(connector)->port;
struct drm_atomic_state *state = pipe_config->base.state;
int bpp;
- int lane_count, slots;
+ int lane_count, slots = 0;
const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
int mst_pbn;
bool constant_n = drm_dp_has_quirk(&intel_dp->desc,
@@ -70,17 +70,23 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
pipe_config->port_clock = intel_dp_max_link_rate(intel_dp);
- if (drm_dp_mst_port_has_audio(&intel_dp->mst_mgr, connector->port))
+ if (drm_dp_mst_port_has_audio(&intel_dp->mst_mgr, port))
pipe_config->has_audio = true;
mst_pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock, bpp);
pipe_config->pbn = mst_pbn;
- slots = drm_dp_atomic_find_vcpi_slots(state, &intel_dp->mst_mgr,
- connector->port, mst_pbn);
- if (slots < 0) {
- DRM_DEBUG_KMS("failed finding vcpi slots:%d\n", slots);
- return false;
+ /* Zombie connectors can't have VCPI slots */
+ if (READ_ONCE(connector->registered)) {
+ slots = drm_dp_atomic_find_vcpi_slots(state,
+ &intel_dp->mst_mgr,
+ port,
+ mst_pbn);
+ if (slots < 0) {
+ DRM_DEBUG_KMS("failed finding vcpi slots:%d\n",
+ slots);
+ return false;
+ }
}
intel_link_compute_m_n(bpp, lane_count,
--
2.17.1
Currently we set intel_connector->mst_port to NULL to signify that the
MST port has been removed from the system so that we can prevent further
action on the port such as connector probes, mode probing, etc.
However, we're going to need access to intel_connector->mst_port in
order to fixup ->best_encoder() so that it can always return the correct
encoder for an MST port to prevent legacy DPMS prop changes from
failing. This should be safe, so instead keep intel_connector->mst_port
always set and instead just check the status of
drm_connector->regustered to signify whether or not the connector has
disappeared from the system.
Changes since v2:
- Add a comment to mst_port_gone (Jani Nikula)
- Change mst_port_gone to a u8 instead of a bool, per the kernel bot.
Apparently bool is discouraged in structs these days
Changes since v4:
- Don't use mst_port_gone at all! Just check if the connector is
registered or not - Daniel Vetter
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/i915/intel_dp_mst.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 43db2e9ac575..aa21742d8634 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -307,9 +307,8 @@ static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector)
struct edid *edid;
int ret;
- if (!intel_dp) {
+ if (!READ_ONCE(connector->registered))
return intel_connector_update_modes(connector, NULL);
- }
edid = drm_dp_mst_get_edid(connector, &intel_dp->mst_mgr, intel_connector->port);
ret = intel_connector_update_modes(connector, edid);
@@ -324,9 +323,10 @@ intel_dp_mst_detect(struct drm_connector *connector, bool force)
struct intel_connector *intel_connector = to_intel_connector(connector);
struct intel_dp *intel_dp = intel_connector->mst_port;
- if (!intel_dp)
+ if (!READ_ONCE(connector->registered))
return connector_status_disconnected;
- return drm_dp_mst_detect_port(connector, &intel_dp->mst_mgr, intel_connector->port);
+ return drm_dp_mst_detect_port(connector, &intel_dp->mst_mgr,
+ intel_connector->port);
}
static void
@@ -366,7 +366,7 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,
int bpp = 24; /* MST uses fixed bpp */
int max_rate, mode_rate, max_lanes, max_link_clock;
- if (!intel_dp)
+ if (!READ_ONCE(connector->registered))
return MODE_ERROR;
if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
@@ -398,7 +398,7 @@ static struct drm_encoder *intel_mst_atomic_best_encoder(struct drm_connector *c
struct intel_dp *intel_dp = intel_connector->mst_port;
struct intel_crtc *crtc = to_intel_crtc(state->crtc);
- if (!intel_dp)
+ if (!READ_ONCE(connector->registered))
return NULL;
return &intel_dp->mst_encoders[crtc->pipe]->base.base;
}
@@ -499,7 +499,6 @@ static void intel_dp_register_mst_connector(struct drm_connector *connector)
static void intel_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
struct drm_connector *connector)
{
- struct intel_connector *intel_connector = to_intel_connector(connector);
struct drm_i915_private *dev_priv = to_i915(connector->dev);
DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, connector->name);
@@ -508,10 +507,6 @@ static void intel_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
if (dev_priv->fbdev)
drm_fb_helper_remove_one_connector(&dev_priv->fbdev->helper,
connector);
- /* prevent race with the check in ->detect */
- drm_modeset_lock(&connector->dev->mode_config.connection_mutex, NULL);
- intel_connector->mst_port = NULL;
- drm_modeset_unlock(&connector->dev->mode_config.connection_mutex);
drm_connector_put(connector);
}
--
2.17.1
As mentioned in the previous commit, we currently prevent new modesets
on recently-removed MST connectors by returning no encoder from our
->best_encoder() callback once the MST port has disappeared. This is
wrong however, because it prevents legacy modesetting users from being
able to disable CRTCs on MST connectors after the connector's respective
topology has disappeared.
So, fix this by instead by just always returning a valid encoder.
Changes since v2:
- Remove usage of atomic MST helper for now, since that got replaced
with a much simpler solution
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/nouveau/dispnv50/disp.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 9f32b10c7c29..31b94bc9ec90 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -843,22 +843,16 @@ nv50_mstc_atomic_best_encoder(struct drm_connector *connector,
{
struct nv50_head *head = nv50_head(connector_state->crtc);
struct nv50_mstc *mstc = nv50_mstc(connector);
- if (mstc->port) {
- struct nv50_mstm *mstm = mstc->mstm;
- return &mstm->msto[head->base.index]->encoder;
- }
- return NULL;
+
+ return &mstc->mstm->msto[head->base.index]->encoder;
}
static struct drm_encoder *
nv50_mstc_best_encoder(struct drm_connector *connector)
{
struct nv50_mstc *mstc = nv50_mstc(connector);
- if (mstc->port) {
- struct nv50_mstm *mstm = mstc->mstm;
- return &mstm->msto[0]->encoder;
- }
- return NULL;
+
+ return &mstc->mstm->msto[0]->encoder;
}
static enum drm_mode_status
--
2.17.1
With the exception of modesets which would switch the DPMS state of a
connector from on to off, we want to make sure that we disallow all
modesets which would result in enabling a new monitor or a new mode
configuration on a monitor if the connector for the display in question
is no longer registered. This allows us to stop userspace from trying to
enable new displays on connectors for an MST topology that were just
removed from the system, without preventing userspace from disabling
DPMS on those connectors.
Changes since v5:
- Fix typo in comment, nothing else
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/drm_atomic_helper.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 6f66777dca4b..e6a2cf72de5e 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -319,6 +319,26 @@ update_connector_routing(struct drm_atomic_state *state,
return 0;
}
+ crtc_state = drm_atomic_get_new_crtc_state(state,
+ new_connector_state->crtc);
+ /*
+ * For compatibility with legacy users, we want to make sure that
+ * we allow DPMS On->Off modesets on unregistered connectors. Modesets
+ * which would result in anything else must be considered invalid, to
+ * avoid turning on new displays on dead connectors.
+ *
+ * Since the connector can be unregistered at any point during an
+ * atomic check or commit, this is racy. But that's OK: all we care
+ * about is ensuring that userspace can't do anything but shut off the
+ * display on a connector that was destroyed after its been notified,
+ * not before.
+ */
+ if (!READ_ONCE(connector->registered) && crtc_state->active) {
+ DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] is not registered\n",
+ connector->base.id, connector->name);
+ return -EINVAL;
+ }
+
funcs = connector->helper_private;
if (funcs->atomic_best_encoder)
@@ -363,7 +383,6 @@ update_connector_routing(struct drm_atomic_state *state,
set_best_encoder(state, new_connector_state, new_encoder);
- crtc_state = drm_atomic_get_new_crtc_state(state, new_connector_state->crtc);
crtc_state->connectors_changed = true;
DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",
--
2.17.1
Currently, i915 appears to rely on blocking modesets on
no-longer-present MSTB ports by simply returning NULL for
->best_encoder(), which in turn causes any new atomic commits that don't
disable the CRTC to fail. This is wrong however, since we still want to
allow userspace to disable CRTCs on no-longer-present MSTB ports by
changing the DPMS state to off and this still requires that we retrieve
an encoder.
So, fix this by always returning a valid encoder regardless of the state
of the MST port.
Changes since v1:
- Remove mst atomic helper, since this got replaced with a much simpler
solution
Signed-off-by: Lyude Paul <lyude(a)redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/i915/intel_dp_mst.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 0f14c0d1669c..7f155b4f1a7d 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -404,8 +404,6 @@ static struct drm_encoder *intel_mst_atomic_best_encoder(struct drm_connector *c
struct intel_dp *intel_dp = intel_connector->mst_port;
struct intel_crtc *crtc = to_intel_crtc(state->crtc);
- if (!READ_ONCE(connector->registered))
- return NULL;
return &intel_dp->mst_encoders[crtc->pipe]->base.base;
}
--
2.17.1