On Thu, 31 Mar 2022 11:25:43 +0200, Heikki Krogerus wrote: > > On Thu, Mar 31, 2022 at 11:12:55AM +0200, Takashi Iwai wrote: > > > > > - if (!strcmp(dev->driver->name, "i915") && > > > > > + if (dev->driver && !strcmp(dev->driver->name, "i915") && > > > > > > > > Can NULL dev->driver be really seen? I thought the components are > > > > added by the drivers, hence they ought to have the driver field set. > > > > But there can be corner cases I overlooked. > > > > > > > > > > > > thanks, > > > > > > > > Takashi > > > > > > Hi Takashi, > > > > > > When I try using component_add in a different driver (usb4 in my > > > case), I think dev->driver here is NULL because the i915 drivers do > > > not have their component master fully bound when this new component is > > > registered. When I test it, it seems to be causing a crash. > > > > Hm, from where component_add*() is called? Basically dev->driver must > > be already set before the corresponding driver gets bound at > > __driver_probe_deviec(). So, if the device is added to component from > > the corresponding driver's probe, dev->driver must be non-NULL. > > The code that declares a device as component does not have to be the > driver of that device. > > In our case the components are USB ports, and they are devices that > are actually never bind to any drivers: drivers/usb/core/port.c OK, that's what I wanted to know. It'd be helpful if it's more clearly mentioned in the commit log. BTW, the same problem must be seen in MEI drivers, too. Takashi
