In the cleanup path of the MSM DP driver the DP driver's debugfs files are destroyed by invoking debugfs_remove_recursive() on debug->root, which during initialization has been set to minor->debugfs_root.
To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go.
By choosing to put the debugfs files in a subdirectory, based on the name of the associated connector this also solves the problem that these names would collide as support for multiple DP instances are introduced.
One alternative solution to the problem with colliding file names would have been to put keep track of the individual files and put them under the connector's debugfs directory. But while the drm_connector has been allocated, its associated debugfs directory has not been created at the time of initialization of the dp_debug.
Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org ---
This depends on https://lore.kernel.org/linux-arm-msm/20211010030435.4000642-1-bjorn.anderss... reducing the connector from a double pointer.
drivers/gpu/drm/msm/dp/dp_debug.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c index da4323556ef3..67da4c69eca1 100644 --- a/drivers/gpu/drm/msm/dp/dp_debug.c +++ b/drivers/gpu/drm/msm/dp/dp_debug.c @@ -210,26 +210,29 @@ static const struct file_operations test_active_fops = { static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor) { int rc = 0; + char path[64]; struct dp_debug_private *debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
- debugfs_create_file("dp_debug", 0444, minor->debugfs_root, + snprintf(path, sizeof(path), "msm_dp-%s", debug->connector->name); + + debug->root = debugfs_create_dir(path, minor->debugfs_root); + + debugfs_create_file("dp_debug", 0444, debug->root, debug, &dp_debug_fops);
debugfs_create_file("msm_dp_test_active", 0444, - minor->debugfs_root, + debug->root, debug, &test_active_fops);
debugfs_create_file("msm_dp_test_data", 0444, - minor->debugfs_root, + debug->root, debug, &dp_test_data_fops);
debugfs_create_file("msm_dp_test_type", 0444, - minor->debugfs_root, + debug->root, debug, &dp_test_type_fops);
- debug->root = minor->debugfs_root; - return rc; }
On 2021-10-15 16:17, Bjorn Andersson wrote:
In the cleanup path of the MSM DP driver the DP driver's debugfs files are destroyed by invoking debugfs_remove_recursive() on debug->root, which during initialization has been set to minor->debugfs_root.
To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go.
By choosing to put the debugfs files in a subdirectory, based on the name of the associated connector this also solves the problem that these names would collide as support for multiple DP instances are introduced.
One alternative solution to the problem with colliding file names would have been to put keep track of the individual files and put them under the connector's debugfs directory. But while the drm_connector has been allocated, its associated debugfs directory has not been created at the time of initialization of the dp_debug.
Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
I have been thinking about this problem ever since multi-DP has been posted :) Creating sub-directories seems right but at the moment it looks like IGT which uses these debugfs nodes doesnt check sub-directories:
https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tools/msm_dp_...
It looks for the DP debugfs nodes under /sys/kernel/debug/dri/*/
We have to fix IGT too to be able to handle multi-DP cases. I will try to come up with a proposal to address this.
Till then, can we go with the other solution to keep track of the dentries?
This depends on https://lore.kernel.org/linux-arm-msm/20211010030435.4000642-1-bjorn.anderss... reducing the connector from a double pointer.
drivers/gpu/drm/msm/dp/dp_debug.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c index da4323556ef3..67da4c69eca1 100644 --- a/drivers/gpu/drm/msm/dp/dp_debug.c +++ b/drivers/gpu/drm/msm/dp/dp_debug.c @@ -210,26 +210,29 @@ static const struct file_operations test_active_fops = { static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor) { int rc = 0;
- char path[64]; struct dp_debug_private *debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
- debugfs_create_file("dp_debug", 0444, minor->debugfs_root,
snprintf(path, sizeof(path), "msm_dp-%s", debug->connector->name);
debug->root = debugfs_create_dir(path, minor->debugfs_root);
debugfs_create_file("dp_debug", 0444, debug->root, debug, &dp_debug_fops);
debugfs_create_file("msm_dp_test_active", 0444,
minor->debugfs_root,
debug->root, debug, &test_active_fops);debugfs_create_file("msm_dp_test_data", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_data_fops);debugfs_create_file("msm_dp_test_type", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_type_fops);
- debug->root = minor->debugfs_root;
- return rc;
}
On Fri 15 Oct 16:53 PDT 2021, abhinavk@codeaurora.org wrote:
On 2021-10-15 16:17, Bjorn Andersson wrote:
In the cleanup path of the MSM DP driver the DP driver's debugfs files are destroyed by invoking debugfs_remove_recursive() on debug->root, which during initialization has been set to minor->debugfs_root.
To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go.
By choosing to put the debugfs files in a subdirectory, based on the name of the associated connector this also solves the problem that these names would collide as support for multiple DP instances are introduced.
One alternative solution to the problem with colliding file names would have been to put keep track of the individual files and put them under the connector's debugfs directory. But while the drm_connector has been allocated, its associated debugfs directory has not been created at the time of initialization of the dp_debug.
Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
I have been thinking about this problem ever since multi-DP has been posted :) Creating sub-directories seems right but at the moment it looks like IGT which uses these debugfs nodes doesnt check sub-directories:
https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tools/msm_dp_...
It looks for the DP debugfs nodes under /sys/kernel/debug/dri/*/
We have to fix IGT too to be able to handle multi-DP cases. I will try to come up with a proposal to address this.
Till then, can we go with the other solution to keep track of the dentries?
I'm afraid I don't see what you're proposing.
Afaict we need one set of dp_test{type,active,data} per DP controller, so even doing this by keeping track of the dentries requires that we rename the files based on some identifier (id or connector name) - which will cause igt to break.
As such, I think the practical path forward is that we merge the multi-DP series as currently proposed. This will not cause any issues on single-DP systems, but on multi-DP systems we will have warnings about duplicate debugfs entries in the kernel logs.
Then you can figure out how to rework igt to deal with the multiple DP instances and update the dp_debug interface accordingly.
Which also implies that we should hold this patch back. But if we go that path, I think we should fix dp_debug_deinit() so that it doesn't remove /sys/kernel/debug/dri/128 when the DP driver is unloaded.
Regards, Bjorn
This depends on https://lore.kernel.org/linux-arm-msm/20211010030435.4000642-1-bjorn.anderss... reducing the connector from a double pointer.
drivers/gpu/drm/msm/dp/dp_debug.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c index da4323556ef3..67da4c69eca1 100644 --- a/drivers/gpu/drm/msm/dp/dp_debug.c +++ b/drivers/gpu/drm/msm/dp/dp_debug.c @@ -210,26 +210,29 @@ static const struct file_operations test_active_fops = { static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor) { int rc = 0;
- char path[64]; struct dp_debug_private *debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
- debugfs_create_file("dp_debug", 0444, minor->debugfs_root,
snprintf(path, sizeof(path), "msm_dp-%s", debug->connector->name);
debug->root = debugfs_create_dir(path, minor->debugfs_root);
debugfs_create_file("dp_debug", 0444, debug->root, debug, &dp_debug_fops);
debugfs_create_file("msm_dp_test_active", 0444,
minor->debugfs_root,
debug->root, debug, &test_active_fops);debugfs_create_file("msm_dp_test_data", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_data_fops);debugfs_create_file("msm_dp_test_type", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_type_fops);
- debug->root = minor->debugfs_root;
- return rc;
}
Hi Bjorn
On 2021-10-17 09:42, Bjorn Andersson wrote:
On Fri 15 Oct 16:53 PDT 2021, abhinavk@codeaurora.org wrote:
On 2021-10-15 16:17, Bjorn Andersson wrote:
In the cleanup path of the MSM DP driver the DP driver's debugfs files are destroyed by invoking debugfs_remove_recursive() on debug->root, which during initialization has been set to minor->debugfs_root.
To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go.
By choosing to put the debugfs files in a subdirectory, based on the name of the associated connector this also solves the problem that these names would collide as support for multiple DP instances are introduced.
One alternative solution to the problem with colliding file names would have been to put keep track of the individual files and put them under the connector's debugfs directory. But while the drm_connector has been allocated, its associated debugfs directory has not been created at the time of initialization of the dp_debug.
Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
I have been thinking about this problem ever since multi-DP has been posted :) Creating sub-directories seems right but at the moment it looks like IGT which uses these debugfs nodes doesnt check sub-directories:
https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tools/msm_dp_...
It looks for the DP debugfs nodes under /sys/kernel/debug/dri/*/
We have to fix IGT too to be able to handle multi-DP cases. I will try to come up with a proposal to address this.
Till then, can we go with the other solution to keep track of the dentries?
I'm afraid I don't see what you're proposing.
Afaict we need one set of dp_test{type,active,data} per DP controller, so even doing this by keeping track of the dentries requires that we rename the files based on some identifier (id or connector name) - which will cause igt to break.
Yes, I also thought the same that there needs to be some identifier.
"To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go"
I guess I misunderstood your statement in the commit text thinking that you had some other way to keep track of the dentries as it mentioned that use a subdirectory OR keep track of each dentry.
As such, I think the practical path forward is that we merge the multi-DP series as currently proposed. This will not cause any issues on single-DP systems, but on multi-DP systems we will have warnings about duplicate debugfs entries in the kernel logs.
Then you can figure out how to rework igt to deal with the multiple DP instances and update the dp_debug interface accordingly.
Fine with me, I will take care of this.
Which also implies that we should hold this patch back. But if we go that path, I think we should fix dp_debug_deinit() so that it doesn't remove /sys/kernel/debug/dri/128 when the DP driver is unloaded.
Yes, lets hold this patch back till I fix multi-DP for IGT.
Regards, Bjorn
This depends on https://lore.kernel.org/linux-arm-msm/20211010030435.4000642-1-bjorn.anderss... reducing the connector from a double pointer.
drivers/gpu/drm/msm/dp/dp_debug.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c index da4323556ef3..67da4c69eca1 100644 --- a/drivers/gpu/drm/msm/dp/dp_debug.c +++ b/drivers/gpu/drm/msm/dp/dp_debug.c @@ -210,26 +210,29 @@ static const struct file_operations test_active_fops = { static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor) { int rc = 0;
- char path[64]; struct dp_debug_private *debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
- debugfs_create_file("dp_debug", 0444, minor->debugfs_root,
snprintf(path, sizeof(path), "msm_dp-%s", debug->connector->name);
debug->root = debugfs_create_dir(path, minor->debugfs_root);
debugfs_create_file("dp_debug", 0444, debug->root, debug, &dp_debug_fops);
debugfs_create_file("msm_dp_test_active", 0444,
minor->debugfs_root,
debug->root, debug, &test_active_fops);debugfs_create_file("msm_dp_test_data", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_data_fops);debugfs_create_file("msm_dp_test_type", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_type_fops);
- debug->root = minor->debugfs_root;
- return rc;
}
On Mon 18 Oct 11:07 PDT 2021, abhinavk@codeaurora.org wrote:
Hi Bjorn
On 2021-10-17 09:42, Bjorn Andersson wrote:
On Fri 15 Oct 16:53 PDT 2021, abhinavk@codeaurora.org wrote:
On 2021-10-15 16:17, Bjorn Andersson wrote:
In the cleanup path of the MSM DP driver the DP driver's debugfs files are destroyed by invoking debugfs_remove_recursive() on debug->root, which during initialization has been set to minor->debugfs_root.
To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go.
By choosing to put the debugfs files in a subdirectory, based on the name of the associated connector this also solves the problem that these names would collide as support for multiple DP instances are introduced.
One alternative solution to the problem with colliding file names would have been to put keep track of the individual files and put them under the connector's debugfs directory. But while the drm_connector has been allocated, its associated debugfs directory has not been created at the time of initialization of the dp_debug.
Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
I have been thinking about this problem ever since multi-DP has been posted :) Creating sub-directories seems right but at the moment it looks like IGT which uses these debugfs nodes doesnt check sub-directories:
https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tools/msm_dp_...
It looks for the DP debugfs nodes under /sys/kernel/debug/dri/*/
We have to fix IGT too to be able to handle multi-DP cases. I will try to come up with a proposal to address this.
Till then, can we go with the other solution to keep track of the dentries?
I'm afraid I don't see what you're proposing.
Afaict we need one set of dp_test{type,active,data} per DP controller, so even doing this by keeping track of the dentries requires that we rename the files based on some identifier (id or connector name) - which will cause igt to break.
Yes, I also thought the same that there needs to be some identifier.
"To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go"
I guess I misunderstood your statement in the commit text thinking that you had some other way to keep track of the dentries as it mentioned that use a subdirectory OR keep track of each dentry.
No, I did write that code as well and then ditched it.
Unfortunately I don't think it would help you, because we still need to add some identifier to the file names and preferably we should add that to the single case as well to make things consistent.
As such, I think the practical path forward is that we merge the multi-DP series as currently proposed. This will not cause any issues on single-DP systems, but on multi-DP systems we will have warnings about duplicate debugfs entries in the kernel logs.
Then you can figure out how to rework igt to deal with the multiple DP instances and update the dp_debug interface accordingly.
Fine with me, I will take care of this.
Cool, thanks.
Regards, Bjorn
Which also implies that we should hold this patch back. But if we go that path, I think we should fix dp_debug_deinit() so that it doesn't remove /sys/kernel/debug/dri/128 when the DP driver is unloaded.
Yes, lets hold this patch back till I fix multi-DP for IGT.
Regards, Bjorn
This depends on https://lore.kernel.org/linux-arm-msm/20211010030435.4000642-1-bjorn.anderss... reducing the connector from a double pointer.
drivers/gpu/drm/msm/dp/dp_debug.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c index da4323556ef3..67da4c69eca1 100644 --- a/drivers/gpu/drm/msm/dp/dp_debug.c +++ b/drivers/gpu/drm/msm/dp/dp_debug.c @@ -210,26 +210,29 @@ static const struct file_operations test_active_fops = { static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor) { int rc = 0;
- char path[64]; struct dp_debug_private *debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
- debugfs_create_file("dp_debug", 0444, minor->debugfs_root,
snprintf(path, sizeof(path), "msm_dp-%s", debug->connector->name);
debug->root = debugfs_create_dir(path, minor->debugfs_root);
debugfs_create_file("dp_debug", 0444, debug->root, debug, &dp_debug_fops);
debugfs_create_file("msm_dp_test_active", 0444,
minor->debugfs_root,
debug->root, debug, &test_active_fops);debugfs_create_file("msm_dp_test_data", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_data_fops);debugfs_create_file("msm_dp_test_type", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_type_fops);
- debug->root = minor->debugfs_root;
- return rc;
}
On 2021-10-18 11:36, Bjorn Andersson wrote:
On Mon 18 Oct 11:07 PDT 2021, abhinavk@codeaurora.org wrote:
Hi Bjorn
On 2021-10-17 09:42, Bjorn Andersson wrote:
On Fri 15 Oct 16:53 PDT 2021, abhinavk@codeaurora.org wrote:
On 2021-10-15 16:17, Bjorn Andersson wrote:
In the cleanup path of the MSM DP driver the DP driver's debugfs files are destroyed by invoking debugfs_remove_recursive() on debug->root, which during initialization has been set to minor->debugfs_root.
To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go.
By choosing to put the debugfs files in a subdirectory, based on the name of the associated connector this also solves the problem that these names would collide as support for multiple DP instances are introduced.
One alternative solution to the problem with colliding file names would have been to put keep track of the individual files and put them under the connector's debugfs directory. But while the drm_connector has been allocated, its associated debugfs directory has not been created at the time of initialization of the dp_debug.
Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
I have been thinking about this problem ever since multi-DP has been posted :) Creating sub-directories seems right but at the moment it looks like IGT which uses these debugfs nodes doesnt check sub-directories:
https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tools/msm_dp_...
It looks for the DP debugfs nodes under /sys/kernel/debug/dri/*/
We have to fix IGT too to be able to handle multi-DP cases. I will try to come up with a proposal to address this.
Till then, can we go with the other solution to keep track of the dentries?
I'm afraid I don't see what you're proposing.
Afaict we need one set of dp_test{type,active,data} per DP controller, so even doing this by keeping track of the dentries requires that we rename the files based on some identifier (id or connector name) - which will cause igt to break.
Yes, I also thought the same that there needs to be some identifier.
"To allow cleaning up the DP driver's debugfs files either each dentry needs to be kept track of or the files needs to be put in a subdirectory which can be removed in one go"
I guess I misunderstood your statement in the commit text thinking that you had some other way to keep track of the dentries as it mentioned that use a subdirectory OR keep track of each dentry.
No, I did write that code as well and then ditched it.
Unfortunately I don't think it would help you, because we still need to add some identifier to the file names and preferably we should add that to the single case as well to make things consistent.
As such, I think the practical path forward is that we merge the multi-DP series as currently proposed. This will not cause any issues on single-DP systems, but on multi-DP systems we will have warnings about duplicate debugfs entries in the kernel logs.
Then you can figure out how to rework igt to deal with the multiple DP instances and update the dp_debug interface accordingly.
Fine with me, I will take care of this.
Cool, thanks.
Regards, Bjorn
Following up on this, Rob has posted the igt change today which i acked. https://patchwork.freedesktop.org/patch/465930/ With this in place, we can actually go ahead with this change.
Hence,
Reviewed-by: Abhinav Kumar quic_abhinavk@quicinc.com
Which also implies that we should hold this patch back. But if we go that path, I think we should fix dp_debug_deinit() so that it doesn't remove /sys/kernel/debug/dri/128 when the DP driver is unloaded.
Yes, lets hold this patch back till I fix multi-DP for IGT.
Regards, Bjorn
This depends on https://lore.kernel.org/linux-arm-msm/20211010030435.4000642-1-bjorn.anderss... reducing the connector from a double pointer.
drivers/gpu/drm/msm/dp/dp_debug.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c index da4323556ef3..67da4c69eca1 100644 --- a/drivers/gpu/drm/msm/dp/dp_debug.c +++ b/drivers/gpu/drm/msm/dp/dp_debug.c @@ -210,26 +210,29 @@ static const struct file_operations test_active_fops = { static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor) { int rc = 0;
- char path[64]; struct dp_debug_private *debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
- debugfs_create_file("dp_debug", 0444, minor->debugfs_root,
snprintf(path, sizeof(path), "msm_dp-%s", debug->connector->name);
debug->root = debugfs_create_dir(path, minor->debugfs_root);
debugfs_create_file("dp_debug", 0444, debug->root, debug, &dp_debug_fops);
debugfs_create_file("msm_dp_test_active", 0444,
minor->debugfs_root,
debug->root, debug, &test_active_fops);debugfs_create_file("msm_dp_test_data", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_data_fops);debugfs_create_file("msm_dp_test_type", 0444,
minor->debugfs_root,
debug->root, debug, &dp_test_type_fops);
- debug->root = minor->debugfs_root;
- return rc;
}
dri-devel@lists.freedesktop.org
-
abhinavk＠codeaurora.org -
Bjorn Andersson