Messages in this thread | | | Date | Wed, 27 Sep 2023 07:57:18 +0200 | From | Greg KH <> | Subject | Re: [RESEND PATCH] driver core: Clear FWNODE_FLAG_LINKS_ADDED in device_links_purge() |
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On Wed, Sep 27, 2023 at 10:30:10AM +0800, Zhenhua Huang wrote: > Flag FWNODE_FLAG_LINKS_ADDED stops fwnode links creation. Current kernel > only adds it once after fwnode links creation in fw_devlink_parse_fwnode(). > After that even device links being purged, the flag will not be cleared. > > Fwnode links are converted to device links and will not be added back > forever in normal case. Essentially if a device is registered and > unregisted (also deleted) before it is probed (due to missing fwlink > dependencies, abort in device_links_check_suppliers), the fwlink is not > setup next when device is newly created again. This means the probe gets > called without meeting all dependencies. > > It usuallly happens in the case of a glue driver. Of_platform_populate() > allows us to populate subnodes. We may do it in ancestor node probing > function, then check subnode's probing status because there may be chances > that suppliers of subnode are not ready. We may further need to do > of_platform_depopulate(which purges device links) and in some time > of_platform_populate() again. Such case we miss fwnode links(so that device > links) during second time of populating subnodes. > > Fix it by Clearing FWNODE_FLAG_LINKS_ADDED flag in purging device link > func, indicates both fwnode links and device links are absent. > > Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com> > --- > drivers/base/core.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index b7d7f41..2a1975d 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -1630,6 +1630,10 @@ static void device_links_purge(struct device *dev) > __device_link_del(&link->kref); > } > > + /* Clear flags in fwnode. Give a chance to create fwnode link again */ > + if (dev->fwnode) > + dev->fwnode->flags &= ~FWNODE_FLAG_LINKS_ADDED; > + > device_links_write_unlock(); > } > > -- > 2.7.4 >
What commit id does this fix?
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