export_imc_mode_and_cmd() function which creates the debugfs interface for imc-mode and imc-command, is invoked when each nest pmu units is registered. When the first nest pmu unit is registered, export_imc_mode_and_cmd() creates 'imc' directory under `/debug/powerpc/`. In the subsequent invocations debugfs_create_dir() function returns, since the directory already exists.
The recent commit <c33d442328f55> (debugfs: make error message a bit more verbose), throws a warning if we try to invoke `debugfs_create_dir()` with an already existing directory name. Address this warning by searching for an existing 'imc' directory, and do not invoke debugfs_create_dir(), if the debugfs interface for imc already exists. This patch is based on: https://lists.ozlabs.org/pipermail/linuxppc-dev/2019-August/195898.html Signed-off-by: Anju T Sudhakar <a...@linux.vnet.ibm.com> Tested-by: Nageswara R Sastry <rnsas...@linux.vnet.ibm.com> --- Changes from v1 -> v2 * Minor changes in the commit message. ------- arch/powerpc/platforms/powernv/opal-imc.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c index e04b20625cb9..fc2f0e60a44d 100644 --- a/arch/powerpc/platforms/powernv/opal-imc.c +++ b/arch/powerpc/platforms/powernv/opal-imc.c @@ -55,14 +55,19 @@ static void export_imc_mode_and_cmd(struct device_node *node, static u64 loc, *imc_mode_addr, *imc_cmd_addr; char mode[16], cmd[16]; u32 cb_offset; + struct dentry *dir = NULL; struct imc_mem_info *ptr = pmu_ptr->mem_info; + + /* Return, if 'imc' interface already exists */ + dir = debugfs_lookup("imc", powerpc_debugfs_root); + if (dir) { + dput(dir); + return; + } imc_debugfs_parent = debugfs_create_dir("imc", powerpc_debugfs_root); - /* - * Return here, either because 'imc' directory already exists, - * Or failed to create a new one. - */ + /* Return here, if failed to create the directory */ if (!imc_debugfs_parent) return; -- 2.20.1
