| Message ID | 1450868368-5650-4-git-send-email-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Wed, Dec 23, 2015 at 11:59:26AM +0100, Marek Szyprowski wrote: > From: Tomeu Vizoso <tomeu.vizoso@collabora.com> > > Allow implementations of the match() callback in struct bus_type to > return errors and if it's -EPROBE_DEFER then queue the device for > deferred probing. > > This is useful to buses such as AMBA in which devices are registered > before their matching information can be retrieved from the HW > (typically because a clock driver hasn't probed yet). > > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> > [changed if-else code structure, adjusted documentation to match the code, > extended comments] > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> This patch _really_ needs an ack from Greg before I can merge it. DRIVER CORE, KOBJECTS, DEBUGFS, KERNFS AND SYSFS M: Greg Kroah-Hartman <gregkh@linuxfoundation.org> T: git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.gitS: Supported F: Documentation/kobject.txt F: drivers/base/ alternatively, the whole series should be taken by Greg, with my ack for the amba and ARM bits. Given that Greg is unlikely to respond this close to the merge window (he's not responded to my messages about the amba-pl011 driver having been messed up by the wrong patch set being taken...) I think this has basically missed the 4.5 merge window. Sorry.
On Mon, Jan 04, 2016 at 04:31:00PM +0000, Russell King - ARM Linux wrote: > On Wed, Dec 23, 2015 at 11:59:26AM +0100, Marek Szyprowski wrote: > > From: Tomeu Vizoso <tomeu.vizoso@collabora.com> > > > > Allow implementations of the match() callback in struct bus_type to > > return errors and if it's -EPROBE_DEFER then queue the device for > > deferred probing. > > > > This is useful to buses such as AMBA in which devices are registered > > before their matching information can be retrieved from the HW > > (typically because a clock driver hasn't probed yet). > > > > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> > > [changed if-else code structure, adjusted documentation to match the code, > > extended comments] > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> > > This patch _really_ needs an ack from Greg before I can merge it. > > DRIVER CORE, KOBJECTS, DEBUGFS, KERNFS AND SYSFS > M: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > T: git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.gitS: Supported > F: Documentation/kobject.txt > F: drivers/base/ > > alternatively, the whole series should be taken by Greg, with my ack > for the amba and ARM bits. > > Given that Greg is unlikely to respond this close to the merge window > (he's not responded to my messages about the amba-pl011 driver having > been messed up by the wrong patch set being taken...) I think this has > basically missed the 4.5 merge window. Sorry. I've been on vacation, so give me a week or so to catch up on everything... And yes, this missed the 4.5 merge window, that closed last week for my trees. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Greg, On 2016-01-04 18:12, Greg Kroah-Hartman wrote: > On Mon, Jan 04, 2016 at 04:31:00PM +0000, Russell King - ARM Linux wrote: >> On Wed, Dec 23, 2015 at 11:59:26AM +0100, Marek Szyprowski wrote: >>> From: Tomeu Vizoso <tomeu.vizoso@collabora.com> >>> >>> Allow implementations of the match() callback in struct bus_type to >>> return errors and if it's -EPROBE_DEFER then queue the device for >>> deferred probing. >>> >>> This is useful to buses such as AMBA in which devices are registered >>> before their matching information can be retrieved from the HW >>> (typically because a clock driver hasn't probed yet). >>> >>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> >>> [changed if-else code structure, adjusted documentation to match the code, >>> extended comments] >>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> >>> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> >> This patch _really_ needs an ack from Greg before I can merge it. >> >> DRIVER CORE, KOBJECTS, DEBUGFS, KERNFS AND SYSFS >> M: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >> T: git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.gitS: Supported >> F: Documentation/kobject.txt >> F: drivers/base/ >> >> alternatively, the whole series should be taken by Greg, with my ack >> for the amba and ARM bits. >> >> Given that Greg is unlikely to respond this close to the merge window >> (he's not responded to my messages about the amba-pl011 driver having >> been messed up by the wrong patch set being taken...) I think this has >> basically missed the 4.5 merge window. Sorry. > I've been on vacation, so give me a week or so to catch up on > everything... > > And yes, this missed the 4.5 merge window, that closed last week for my > trees. Could you take a look into this patch? Best regards
diff --git a/Documentation/driver-model/porting.txt b/Documentation/driver-model/porting.txt index 92d86f7..453053f 100644 --- a/Documentation/driver-model/porting.txt +++ b/Documentation/driver-model/porting.txt @@ -340,8 +340,10 @@ comparison: int (*match)(struct device * dev, struct device_driver * drv); -match should return '1' if the driver supports the device, and '0' -otherwise. +match should return positive value if the driver supports the device, +and zero otherwise. It may also return error code (for example +-EPROBE_DEFER) if determining that given driver supports the device is +not possible. When a device is registered, the bus's list of drivers is iterated over. bus->match() is called for each one until a match is found. diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 7399be7..7c3f1f1 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -544,6 +544,7 @@ static int __device_attach_driver(struct device_driver *drv, void *_data) struct device_attach_data *data = _data; struct device *dev = data->dev; bool async_allowed; + int ret; /* * Check if device has already been claimed. This may @@ -554,8 +555,17 @@ static int __device_attach_driver(struct device_driver *drv, void *_data) if (dev->driver) return -EBUSY; - if (!driver_match_device(drv, dev)) + ret = driver_match_device(drv, dev); + if (ret == 0) { + /* no match */ return 0; + } else if (ret == -EPROBE_DEFER) { + dev_dbg(dev, "Device match requests probe deferral\n"); + driver_deferred_probe_add(dev); + } else if (ret < 0) { + dev_dbg(dev, "Bus failed to match device: %d", ret); + return ret; + } /* ret > 0 means positive match */ async_allowed = driver_allows_async_probing(drv); @@ -675,6 +685,7 @@ void device_initial_probe(struct device *dev) static int __driver_attach(struct device *dev, void *data) { struct device_driver *drv = data; + int ret; /* * Lock device and try to bind to it. We drop the error @@ -686,8 +697,17 @@ static int __driver_attach(struct device *dev, void *data) * is an error. */ - if (!driver_match_device(drv, dev)) + ret = driver_match_device(drv, dev); + if (ret == 0) { + /* no match */ return 0; + } else if (ret == -EPROBE_DEFER) { + dev_dbg(dev, "Device match requests probe deferral\n"); + driver_deferred_probe_add(dev); + } else if (ret < 0) { + dev_dbg(dev, "Bus failed to match device: %d", ret); + return ret; + } /* ret > 0 means positive match */ if (dev->parent) /* Needed for USB */ device_lock(dev->parent); diff --git a/include/linux/device.h b/include/linux/device.h index f627ba2..75a2cde 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -70,8 +70,11 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *); * @dev_groups: Default attributes of the devices on the bus. * @drv_groups: Default attributes of the device drivers on the bus. * @match: Called, perhaps multiple times, whenever a new device or driver - * is added for this bus. It should return a nonzero value if the - * given device can be handled by the given driver. + * is added for this bus. It should return a positive value if the + * given device can be handled by the given driver and zero + * otherwise. It may also return error code if determining that + * the driver supports the device is not possible. In case of + * -EPROBE_DEFER it will queue the device for deferred probing. * @uevent: Called when a device is added, removed, or a few other things * that generate uevents to add the environment variables. * @probe: Called when a new device or driver add to this bus, and callback