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The usecase could be f.ex. an i3cdev userspace driver > for a device with broken hotjoin support. If the i3c device > boots slowly, it might be miss the DDA during boot. AI helpped rephrase Allow userspace to request a dynamic address assignment, which is useful for devices with broken hot-join support or devices that boot slowly and may miss the initial DDA during system startup. Need update ABI document Documentation/ABI/testing/sysfs-bus-i3c Frank > > Signed-off-by: David Nyström > --- > Changes in v3: > - Rename sysfs entry from rescan to entdda, Comment: Joshua Yeong > - Link to v2: https://patch.msgid.link/20260122-i3c_rescan-v2-1-84c74a483f03@est.tech > > Changes in v2: > - Improved the commit message with "why". > - Link to v1: https://patch.msgid.link/20260122-i3c_rescan-v1-1-0c17071e232b@est.tech > --- > drivers/i3c/master.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c > index 80dda0e85558..a1d816634a25 100644 > --- a/drivers/i3c/master.c > +++ b/drivers/i3c/master.c > @@ -758,6 +758,29 @@ static ssize_t dev_nack_retry_count_store(struct device *dev, > > static DEVICE_ATTR_RW(dev_nack_retry_count); > > +static ssize_t entdaa_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct i3c_master_controller *master = dev_to_i3cmaster(dev); > + unsigned long val; > + int ret; > + > + ret = kstrtoul(buf, 0, &val); > + if (ret) > + return ret; > + > + if (val) { > + ret = i3c_master_do_daa(master); > + if (ret) > + return ret; > + } > + > + return count; > +} > + > +static DEVICE_ATTR_WO(entdaa); > + > static struct attribute *i3c_masterdev_attrs[] = { > &dev_attr_mode.attr, > &dev_attr_current_master.attr, > @@ -769,6 +792,7 @@ static struct attribute *i3c_masterdev_attrs[] = { > &dev_attr_dynamic_address.attr, > &dev_attr_hdrcap.attr, > &dev_attr_hotjoin.attr, > + &dev_attr_entdaa.attr, > NULL, > }; > ATTRIBUTE_GROUPS(i3c_masterdev); > > --- > base-commit: e3b32dcb9f23e3c3927ef3eec6a5842a988fb574 > change-id: 20260116-i3c_rescan-4921d0b41a00 > > Best regards, > -- > David Nyström >