Messages in this thread | | | From | Saravana Kannan <> | Date | Thu, 11 Aug 2022 18:39:37 -0700 | Subject | Re: [PATCH v1] driver core: Don't probe devices after bus_type.match() probe deferral |
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On Thu, Aug 11, 2022 at 5:56 PM Guenter Roeck <linux@roeck-us.net> wrote: > > On 8/11/22 12:07, Isaac J. Manjarres wrote: > > Both __device_attach_driver() and __driver_attach() check the return > > code of the bus_type.match() function to see if the device needs to be > > added to the deferred probe list. After adding the device to the list, > > the logic attempts to bind the device to the driver anyway, as if the > > device had matched with the driver, which is not correct. > > > > If __device_attach_driver() detects that the device in question is not > > ready to match with a driver on the bus, then it doesn't make sense for > > the device to attempt to bind with the current driver or continue > > attempting to match with any of the other drivers on the bus. So, update > > the logic in __device_attach_driver() to reflect this. > > > > If __driver_attach() detects that a driver tried to match with a device > > that is not ready to match yet, then the driver should not attempt to bind > > with the device. However, the driver can still attempt to match and bind > > with other devices on the bus, as drivers can be bound to multiple > > devices. So, update the logic in __driver_attach() to reflect this. > > > > Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()") > > Reported-by: Guenter Roeck <linux@roeck-us.net> > > Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> > > Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Saravana Kannan <saravanak@google.com>
-Saravana
> > > --- > > drivers/base/dd.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > > > Guenter, > > > > Thanks for testing this patch out. Can you please add your "Tested-by"? > > > > --Isaac > > > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > > index 70f79fc71539..90b31fb141a5 100644 > > --- a/drivers/base/dd.c > > +++ b/drivers/base/dd.c > > @@ -881,6 +881,11 @@ static int __device_attach_driver(struct device_driver *drv, void *_data) > > dev_dbg(dev, "Device match requests probe deferral\n"); > > dev->can_match = true; > > driver_deferred_probe_add(dev); > > + /* > > + * Device can't match with a driver right now, so don't attempt > > + * to match or bind with other drivers on the bus. > > + */ > > + return ret; > > } else if (ret < 0) { > > dev_dbg(dev, "Bus failed to match device: %d\n", ret); > > return ret; > > @@ -1120,6 +1125,11 @@ static int __driver_attach(struct device *dev, void *data) > > dev_dbg(dev, "Device match requests probe deferral\n"); > > dev->can_match = true; > > driver_deferred_probe_add(dev); > > + /* > > + * Driver could not match with device, but may match with > > + * another device on the bus. > > + */ > > + return 0; > > } else if (ret < 0) { > > dev_dbg(dev, "Bus failed to match device: %d\n", ret); > > return ret; > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >
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