On Fri, Dec 27, 2024 at 03:13:06PM +0000, Sudeep Holla wrote: > On Wed, Dec 25, 2024 at 04:20:44PM +0800, Peng Fan (OSS) wrote: > > From: Peng Fan <peng.fan@xxxxxxx> > > > > Two drivers scmi_cpufreq.c and scmi_perf_domain.c both use > > SCMI_PROTCOL_PERF protocol, but with different name, so two scmi devices > > will be created. But the fwnode->dev could only point to one device. > > > > If scmi cpufreq device created earlier, the fwnode->dev will point to > > the scmi cpufreq device. Then the fw_devlink will link performance > > domain user device(consumer) to the scmi cpufreq device(supplier). > > But actually the performance domain user device, such as GPU, should use > > the scmi perf device as supplier. Also if 'cpufreq.off=1' in bootargs, > > the GPU driver will defer probe always, because of the scmi cpufreq > > device not ready. > > > > Because for cpufreq, no need use fw_devlink. So bypass setting fwnode > > for scmi cpufreq device. > > Hi, > > Fixes: 96da4a99ce50 ("firmware: arm_scmi: Set fwnode for the scmi_device") > > Signed-off-by: Peng Fan <peng.fan@xxxxxxx> > > --- > > drivers/firmware/arm_scmi/bus.c | 15 ++++++++++++++- > > 1 file changed, 14 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c > > index 157172a5f2b577ce4f04425f967f548230c1ebed..12190d4dabb65484543044b4424fbe3b67245466 100644 > > --- a/drivers/firmware/arm_scmi/bus.c > > +++ b/drivers/firmware/arm_scmi/bus.c > > @@ -345,6 +345,19 @@ static void __scmi_device_destroy(struct scmi_device *scmi_dev) > > device_unregister(&scmi_dev->dev); > > } > > > > +static int > > +__scmi_device_set_node(struct scmi_device *scmi_dev, struct device_node *np, > > + int protocol, const char *name) > > +{ > > + /* cpufreq device does not need to be supplier from devlink perspective */ > > + if ((protocol == SCMI_PROTOCOL_PERF) && !strcmp(name, "cpufreq")) > > + return 0; > > > > This is just a assumption based on current implementation. What happens > if this is needed. Infact, it is used in the current implementation to > create a dummy clock provider, so for sure with this change that will > break IMO. I agree with Sudeep on this: if you want to exclude some SCMI device from the fw_devlink handling to address the issues with multiple SCMI devices created on the same protocol nodes, cant we just flag this requirement here and avoid to call device_link_add in driver:scmi_set_handle(), instead of killing completely any possibility of referencing phandles (and having device_link_add failing as a consequence of having a NULL supplier) i.e. something like: @bus.c ------ static int __scmi_device_set_node(struct scmi_device *scmi_dev, struct device_node *np, int protocol, const char *name) { if ((protocol == SCMI_PROTOCOL_PERF) && !strcmp(name, "cpufreq")) scmi_dev->avoid_devlink = true; device_set_node(&scmi_dev->dev, of_fwnode_handle(np)); .... and @driver.c ------------- static void scmi_set_handle(struct scmi_device *scmi_dev) { scmi_dev->handle = scmi_handle_get(&scmi_dev->dev); if (scmi_dev->handle && !scmi_dev->avoid_devlink) scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev); } .... so that you can avoid fw_devlink BUT keep the device_node NON-null for the device. This would mean also restoring the pre-existing explicit blacklisting in pinctrl-imx to avoid issues when pinctrl subsystem searches by device_node... ..or I am missing something ? Thanks, Cristian