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@xxxxxxxxxx>
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_compliance.c#L215
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.andersson@xxxxxxxxxx/
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;
}
