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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org On Mon, Nov 17, 2025 at 07:47:05PM +0200, Adrian Hunter wrote: > On 17/11/2025 17:59, Frank Li wrote: > > On Mon, Nov 17, 2025 at 01:36:36PM +0200, Adrian Hunter wrote: > >> On 14/11/2025 22:09, Frank Li wrote: > >>> On Fri, Nov 14, 2025 at 08:13:55PM +0200, Adrian Hunter wrote: > >>>> Add support for Latency Tolerance Reporting (LTR) for Intel controllers. > >>>> > >>>> Implement PM ->set_latency_tolerance() callback to set LTR register values. > >>>> Also expose LTR register values via debugfs. > >>>> > >>>> Signed-off-by: Adrian Hunter > >>>> --- > >>>> > >>>> > >>>> Changes in V2: > >>>> > >>>> Make use of FIELD_PREP() > >>>> Improve handling of values that exceed the maximum > >>>> > >>>> > >>>> .../master/mipi-i3c-hci/mipi-i3c-hci-pci.c | 125 ++++++++++++++++++ > >>>> 1 file changed, 125 insertions(+) > >>>> > >>> ... > >>>> +static void intel_ltr_expose(struct device *dev) > >>>> +{ > >>>> + dev->power.set_latency_tolerance = intel_ltr_set; > >>>> + dev_pm_qos_expose_latency_tolerance(dev); > >>>> +} > >>>> + > >>>> +static void intel_ltr_hide(struct device *dev) > >>>> +{ > >>>> + dev_pm_qos_hide_latency_tolerance(dev); > >>>> + dev->power.set_latency_tolerance = NULL; > >>>> +} > >>>> + > >>>> +static struct dentry *intel_actualize_debugfs_root(bool add) > >>>> +{ > >>>> + static struct dentry *debugfs_root; > >>>> + static DEFINE_MUTEX(lock); > >>>> + static int ref_cnt; > >>>> + > >>>> + guard(mutex)(&lock); > >>>> + > >>>> + ref_cnt += add ? 1 : -1; > >>>> + > >>>> + if (ref_cnt) { > >>>> + if (IS_ERR_OR_NULL(debugfs_root)) > >>>> + debugfs_root = debugfs_create_dir("intel_i3c", NULL); > >>> > >>> I think it'd better to create common "i3c" debugfs root. So your device > >>> use debugfs_create_dir(dev_name(&hci->pci->dev), ...) under this common > >>> root. > >> > >> The debugfs files are being created for the PCI device to contain PCI > >> LTR information. The i3c module has nothing to do with that. > >> > >> Also, currently, there is no module dependency between this PCI driver > >> and i3c, but a dependency would be necessary to coordinate the creation > >> and deletion of an 'i3c' debugfs directory. > >> > >> The extra complexity can't be justified. > > > > Don't post new versin before we close open discussion. I see your post > > patch before this message. > > Sorry, but it is late in the release cycle, and it saves time when we > are in different time zones. > > > > > So, I think not necessary to create to root, which cause complex, (need > > lock, and refer counter). > > So you are OK with V3? In v3, still create "intel_i3c" root dir, how about direct create dev under root debugfs_create_dir(dev_name(&hci->pci->dev), NULL); to reduce unneccesary complex, (like mutex lock and ref counter). Frank > > > > > Frank > > > >> > >>> > >>> ... > >>> > >>>> + > >>>> static const struct mipi_i3c_hci_pci_info intel_info = { > >>>> .init = intel_i3c_init, > >>>> + .exit = intel_exit, > >>>> }; > >>>> > >>>> static int mipi_i3c_hci_pci_probe(struct pci_dev *pci, > >>>> -- > >>>> 2.51.0 > >>>> > >>>> > >>>> -- > >>>> linux-i3c mailing list > >>>> linux-i3c@lists.infradead.org > >>>> http://lists.infradead.org/mailman/listinfo/linux-i3c > >> > >> > >> -- > >> linux-i3c mailing list > >> linux-i3c@lists.infradead.org > >> http://lists.infradead.org/mailman/listinfo/linux-i3c > > > -- > linux-i3c mailing list > linux-i3c@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-i3c -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c