Re: [v3] PCI: tegra194: Fix debugfs directory creation when CONFIG_PCIEASPM is disabled

From: Christophe JAILLET
Date: Mon Apr 07 2025 - 15:48:40 EST


Hi,

Nitpick: PATCH is missing within the [] in the subject.


Le 07/04/2025 à 14:43, Hans Zhang a écrit :
Previously, the debugfs directory was unconditionally created in
tegra_pcie_config_rp() regardless of the CONFIG_PCIEASPM setting.
This led to unnecessary directory creation when ASPM support was disabled.

Move the debugfs directory creation into init_debugfs() which is
conditionally compiled based on CONFIG_PCIEASPM. This ensures:
- The directory is only created when ASPM-related debugfs entries are
needed.
- Proper error handling for directory creation failures.
- Avoids cluttering debugfs with empty directories when ASPM is disabled.

Signed-off-by: Hans Zhang <18255117159@xxxxxxx>
---
Changes since v2:
https://lore.kernel.org/linux-pci/20250406134355.49036-1-18255117159@xxxxxxx/

- Maintainer recommends ignoring the devm_kasprintf return value. The
module should still work correctly. So just a return;

Note, that I'm not a maintainer ;-)

For what it worth:

Reviewed-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>


CJ

Changes since v1:
https://lore.kernel.org/linux-pci/20250405145459.26800-1-18255117159@xxxxxxx/

- The first version was committed incorrectly because the judgment
parameter in "debugfs_remove_recursive" was not noticed.
---
drivers/pci/controller/dwc/pcie-tegra194.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 5103995cd6c7..bc419688527a 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -713,7 +713,16 @@ static void init_host_aspm(struct tegra_pcie_dw *pcie)
static void init_debugfs(struct tegra_pcie_dw *pcie)
{
- debugfs_create_devm_seqfile(pcie->dev, "aspm_state_cnt", pcie->debugfs,
+ struct device *dev = pcie->dev;
+ char *name;
+
+ name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
+ if (!name)
+ return;
+
+ pcie->debugfs = debugfs_create_dir(name, NULL);
+
+ debugfs_create_devm_seqfile(dev, "aspm_state_cnt", pcie->debugfs,
aspm_state_cnt);
}
#else
@@ -1634,7 +1643,6 @@ static void tegra_pcie_deinit_controller(struct tegra_pcie_dw *pcie)
static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
{
struct device *dev = pcie->dev;
- char *name;
int ret;
pm_runtime_enable(dev);
@@ -1664,13 +1672,6 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
goto fail_host_init;
}
- name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
- if (!name) {
- ret = -ENOMEM;
- goto fail_host_init;
- }
-
- pcie->debugfs = debugfs_create_dir(name, NULL);
init_debugfs(pcie);
return ret;

base-commit: a8662bcd2ff152bfbc751cab20f33053d74d0963