Re: [PATCH 2/2] devm-helpers: Add resource managed version of debugfs directory create function

From: Dan Williams
Date: Thu Feb 22 2024 - 13:37:15 EST


Dan Williams wrote:
> Dave Jiang wrote:
> >
> >
> > On 2/22/24 7:58 AM, Marek Behún wrote:
> > > A few drivers register a devm action to remove a debugfs directory,
> > > implementing a one-liner function that calls debufs_remove_recursive().
> > > Help drivers avoid this repeated implementations by adding managed
> > > version of debugfs directory create function.
> > >
> > > Use the new function devm_debugfs_create_dir() in the following
> > > drivers:
> > > drivers/crypto/caam/ctrl.c
> > > drivers/gpu/drm/bridge/ti-sn65dsi86.c
> > > drivers/hwmon/hp-wmi-sensors.c
> > > drivers/hwmon/mr75203.c
> > > drivers/hwmon/pmbus/pmbus_core.c
> > >
> > > Also use the action function devm_debugfs_dir_recursive_drop() in
> > > drivers
> > > drivers/cxl/mem.c
> > > drivers/gpio/gpio-mockup.c
> > >
> > > Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
> > > ---
> > > drivers/crypto/caam/ctrl.c | 16 +++------
> > > drivers/cxl/mem.c | 9 ++---
> > > drivers/gpio/gpio-mockup.c | 11 ++----
> > > drivers/gpu/drm/bridge/ti-sn65dsi86.c | 13 ++------
> > > drivers/hwmon/hp-wmi-sensors.c | 15 ++-------
> > > drivers/hwmon/mr75203.c | 15 +++------
> > > drivers/hwmon/pmbus/pmbus_core.c | 16 +++------
> > > include/linux/devm-helpers.h | 48 +++++++++++++++++++++++++++
> > > 8 files changed, 72 insertions(+), 71 deletions(-)
> > >
[..]
> > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> > index 5303d6942b88..b6f13ba87927 100644
> > --- a/drivers/cxl/cxlmem.h
> > +++ b/drivers/cxl/cxlmem.h
> > @@ -859,6 +859,5 @@ struct cxl_hdm {
> > };
> >
> > struct seq_file;
> > -struct dentry *cxl_debugfs_create_dir(const char *dir);
> > void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds);
> > #endif /* __CXL_MEM_H__ */
> > diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> > index c5c9d8e0d88d..494abe7a54c5 100644
> > --- a/drivers/cxl/mem.c
> > +++ b/drivers/cxl/mem.c
> > @@ -4,6 +4,7 @@
> > #include <linux/device.h>
> > #include <linux/module.h>
> > #include <linux/pci.h>
> > +#include <linux/devm-helpers.h>
> >
> > #include "cxlmem.h"
> > #include "cxlpci.h"
> > @@ -30,11 +31,6 @@ static void enable_suspend(void *data)
> > cxl_mem_active_dec();
> > }
> >
> > -static void remove_debugfs(void *dentry)
> > -{
> > - debugfs_remove_recursive(dentry);
> > -}
> > -
> > static int cxl_mem_dpa_show(struct seq_file *file, void *data)
> > {
> > struct device *dev = file->private;
> > @@ -128,7 +124,10 @@ static int cxl_mem_probe(struct device *dev)
> > if (work_pending(&cxlmd->detach_work))
> > return -EBUSY;
> >
> > - dentry = cxl_debugfs_create_dir(dev_name(dev));
> > + dentry = devm_debugfs_create_dir(dev, dev_name(dev), NULL);
> > + if (IS_ERR(dentry))
> > + return PTR_ERR(dentry);
> > +
>
> No that loses the "cxl" prefix.

So, to be clear, I do see the benefit of removing the
devm_add_action_or_reset() call altogether, but that work is a bit
deeper and should not be tied with all these other cleanups. So I think
from the CXL perspective, please drop these CXL changes out of this
patch. Follow up with a standalone patch, or leave it to drivers/cxl/
folks to create that deeper cleanup.