On Wed, Feb 28, 2024 at 09:21:00PM +0100, Javier Carrasco wrote: > On 28.02.24 19:10, Matthias Kaehlcke wrote: > > On Wed, Feb 28, 2024 at 02:51:33PM +0100, Javier Carrasco wrote: > >> Most of the functionality this driver provides can be used by non-hub > >> devices as well. > >> > >> To account for the hub-specific code, add a flag to the device data > >> structure and check its value for hub-specific code. > >> > >> The 'always_powered_in_supend' attribute is only available for hub > >> devices, keeping the driver's default behavior for non-hub devices (keep > >> on in suspend). > >> > >> Signed-off-by: Javier Carrasco <javier.carra...@wolfvision.net> > >> --- > >> drivers/usb/misc/onboard_usb_dev.c | 25 +++++++++++++++++++++++-- > >> drivers/usb/misc/onboard_usb_dev.h | 10 ++++++++++ > >> 2 files changed, 33 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/usb/misc/onboard_usb_dev.c > >> b/drivers/usb/misc/onboard_usb_dev.c > >> index e1779bd2d126..df0ed172c7ec 100644 > >> --- a/drivers/usb/misc/onboard_usb_dev.c > >> +++ b/drivers/usb/misc/onboard_usb_dev.c > >> @@ -132,7 +132,8 @@ static int __maybe_unused onboard_dev_suspend(struct > >> device *dev) > >> struct usbdev_node *node; > >> bool power_off = true; > >> > >> - if (onboard_dev->always_powered_in_suspend) > >> + if (onboard_dev->always_powered_in_suspend && > >> + !onboard_dev->pdata->is_hub) > >> return 0; > > > > With this non-hub devices would always be powered down, since > > 'always_powerd_in_suspend' is not set for them. This should be: > > > > May I ask you what you meant in v4 with this comment? > > > Even without the sysfs attribute the field 'always_powered_in_suspend' > > could > > be set to true by probe() for non-hub devices.
struct onboard_dev always has the field 'always_powered_in_suspend', even for non-hubs, that don't have the corresponding sysfs attribute. Currently it is left uninitialized (i.e. false) for non-hubs. Instead it could be initialized to true by probe() for non-hubs, which would be semantically correct. With that it wouldn't be necessary to check here whether a device is hub, because the field would provide the necessary information. > > if (!onboard_dev->pdata->is_hub || > > onboard_dev->always_powered_in_suspend) > > > > Checking for the (non-)hub status first is clearer IMO, also it avoids > > an unneccessary check of 'always_powered' for non-hub devices. > > > > That makes sense and will be fixed. > > > Without code context: for hubs there can be multiple device tree nodes > > for the same physical hub chip (e.g. one for the USB2 and another for > > the USB3 part). I suppose this could also be the case for non-hub > > devices. For hubs there is the 'peer-hub' device tree property to > > establish a link between the two USB devices, as a result the onboard > > driver only creates a single platform device (which is desired, > > otherwise two platform devices would be in charge for power sequencing > > the same phyiscal device. For non-hub devices there is currently no such > > link. In many cases I expect there will be just one DT entry even though > > the device has multiple USB interfaces, but it could happen and would > > actually be a more accurate representation. > > > > General support is already there (the code dealing with 'peer-hub'), but > > we'd have to come up with a suitable name. 'peer-device' is the first > > thing that comes to my mind, but there might be better options. If such > > a generic property is added then we should deprecate 'peer-hub', but > > maintain backwards compatibility. > > I have nothing against that, but the first non-hub device that will be > added does not have multiple DT nodes, so I have nothing to test that > extension with real hardware. I see, the XVF3500 is USB 2.0 only, so it isn't suitable for testing. > That could be added in the future, though, if the need ever arises. I expect it will, when a DT maintainer asks the hardware to be represented correctly for a device that is connected to more than one USB bus. IIRC that's how 'peer-hub' was born :) Ok, we can leave it out for now. I might send a dedicated patch after your series landed. If a switch to 'peer-device' or similar is anticipated then it's probably best to deprecate 'peer-hub' ASAP, to avoid it from getting added to more bindings.
