Messages in this thread | | | Date | Thu, 25 Aug 2022 11:22:51 +0200 | Subject | Re: [PATCH v2] driver core: Fix bus_type.match() error handling | From | Marek Szyprowski <> |
| |
On 15.08.2022 23:19, 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 > and that results in any error, 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. > > Cc: Saravana Kannan <saravanak@google.com> > Cc: stable@kernel.org > 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>
This fixes the boot issue observed on Qualcomm APQ8016 based DragonBoard 410c, which I've missed while testing the "amba: Remove deferred device addition" patch. Feel free to add:
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> --- > drivers/base/dd.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > v1 -> v2: > - Fixed the logic in __driver_attach() to allow a driver to continue > attempting to match and bind with devices in case of any error, not > just probe deferral. > > Guenter, > > Can you please give test this patch to make sure it still works for you? > > Thanks, > Isaac > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 70f79fc71539..453eb19a9a27 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; > @@ -1120,9 +1125,18 @@ 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 right now, 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; > + /* > + * Driver could not match with device, but may match with > + * another device on the bus. > + */ > + return 0; > } /* ret > 0 means positive match */ > > if (driver_allows_async_probing(drv)) {
Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
| |