There's no point in adding a device to the deferred probe list if we
know for sure that it doesn't have a matching driver. So, check if a
device can match with a driver before adding it to the deferred probe
list.
Signed-off-by: Saravana Kannan <[email protected]>
---
Geert,
Can you give this a shot for your I2C DMA issue with fw_devlink=on?
-Saravana
drivers/base/dd.c | 6 ++++++
include/linux/device.h | 4 ++++
2 files changed, 10 insertions(+)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 9179825ff646..f18963f42e21 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -123,6 +123,9 @@ static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
void driver_deferred_probe_add(struct device *dev)
{
+ if (!dev->can_match)
+ return;
+
mutex_lock(&deferred_probe_mutex);
if (list_empty(&dev->p->deferred_probe)) {
dev_dbg(dev, "Added to deferred list\n");
@@ -726,6 +729,7 @@ static int driver_probe_device(struct device_driver *drv, struct device *dev)
if (!device_is_registered(dev))
return -ENODEV;
+ dev->can_match = true;
pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
drv->bus->name, __func__, dev_name(dev), drv->name);
@@ -829,6 +833,7 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
return 0;
} else if (ret == -EPROBE_DEFER) {
dev_dbg(dev, "Device match requests probe deferral\n");
+ dev->can_match = true;
driver_deferred_probe_add(dev);
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
@@ -1064,6 +1069,7 @@ static int __driver_attach(struct device *dev, void *data)
return 0;
} else if (ret == -EPROBE_DEFER) {
dev_dbg(dev, "Device match requests probe deferral\n");
+ dev->can_match = true;
driver_deferred_probe_add(dev);
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
diff --git a/include/linux/device.h b/include/linux/device.h
index 7619a84f8ce4..1f9cc1ba78bc 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -438,6 +438,9 @@ struct dev_links_info {
* @state_synced: The hardware state of this device has been synced to match
* the software state of this device by calling the driver/bus
* sync_state() callback.
+ * @can_match: The device has matched with a driver at least once or it is in
+ * a bus (like AMBA) which can't check for matching drivers until
+ * other devices probe successfully.
* @dma_coherent: this particular device is dma coherent, even if the
* architecture supports non-coherent devices.
* @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
@@ -544,6 +547,7 @@ struct device {
bool offline:1;
bool of_node_reused:1;
bool state_synced:1;
+ bool can_match:1;
#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
--
2.30.0.478.g8a0d178c01-goog
On Thu, Feb 18, 2021 at 12:51 AM Saravana Kannan <[email protected]> wrote:
>
> There's no point in adding a device to the deferred probe list if we
> know for sure that it doesn't have a matching driver. So, check if a
> device can match with a driver before adding it to the deferred probe
> list.
What if a matching driver module loads in the meantime?
>
> Signed-off-by: Saravana Kannan <[email protected]>
> ---
> Geert,
>
> Can you give this a shot for your I2C DMA issue with fw_devlink=on?
>
> -Saravana
>
> drivers/base/dd.c | 6 ++++++
> include/linux/device.h | 4 ++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 9179825ff646..f18963f42e21 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -123,6 +123,9 @@ static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
>
> void driver_deferred_probe_add(struct device *dev)
> {
> + if (!dev->can_match)
> + return;
> +
> mutex_lock(&deferred_probe_mutex);
> if (list_empty(&dev->p->deferred_probe)) {
> dev_dbg(dev, "Added to deferred list\n");
> @@ -726,6 +729,7 @@ static int driver_probe_device(struct device_driver *drv, struct device *dev)
> if (!device_is_registered(dev))
> return -ENODEV;
>
> + dev->can_match = true;
> pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
> drv->bus->name, __func__, dev_name(dev), drv->name);
>
> @@ -829,6 +833,7 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
> return 0;
> } else if (ret == -EPROBE_DEFER) {
> dev_dbg(dev, "Device match requests probe deferral\n");
> + dev->can_match = true;
> driver_deferred_probe_add(dev);
> } else if (ret < 0) {
> dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> @@ -1064,6 +1069,7 @@ static int __driver_attach(struct device *dev, void *data)
> return 0;
> } else if (ret == -EPROBE_DEFER) {
> dev_dbg(dev, "Device match requests probe deferral\n");
> + dev->can_match = true;
> driver_deferred_probe_add(dev);
> } else if (ret < 0) {
> dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 7619a84f8ce4..1f9cc1ba78bc 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -438,6 +438,9 @@ struct dev_links_info {
> * @state_synced: The hardware state of this device has been synced to match
> * the software state of this device by calling the driver/bus
> * sync_state() callback.
> + * @can_match: The device has matched with a driver at least once or it is in
> + * a bus (like AMBA) which can't check for matching drivers until
> + * other devices probe successfully.
> * @dma_coherent: this particular device is dma coherent, even if the
> * architecture supports non-coherent devices.
> * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
> @@ -544,6 +547,7 @@ struct device {
> bool offline:1;
> bool of_node_reused:1;
> bool state_synced:1;
> + bool can_match:1;
> #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
> defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
> defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
> --
On Thu, Feb 18, 2021 at 9:18 AM Rafael J. Wysocki <[email protected]> wrote:
>
> On Thu, Feb 18, 2021 at 12:51 AM Saravana Kannan <[email protected]> wrote:
> >
> > There's no point in adding a device to the deferred probe list if we
> > know for sure that it doesn't have a matching driver. So, check if a
> > device can match with a driver before adding it to the deferred probe
> > list.
>
> What if a matching driver module loads in the meantime?
Driver registration always triggers a match attempt and this flag will
get set at that point. Yes, the user can disable autoprobe, but
that'll block deferred probes too.
-Saravana
>
> >
> > Signed-off-by: Saravana Kannan <[email protected]>
> > ---
> > Geert,
> >
> > Can you give this a shot for your I2C DMA issue with fw_devlink=on?
> >
> > -Saravana
> >
> > drivers/base/dd.c | 6 ++++++
> > include/linux/device.h | 4 ++++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> > index 9179825ff646..f18963f42e21 100644
> > --- a/drivers/base/dd.c
> > +++ b/drivers/base/dd.c
> > @@ -123,6 +123,9 @@ static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
> >
> > void driver_deferred_probe_add(struct device *dev)
> > {
> > + if (!dev->can_match)
> > + return;
> > +
> > mutex_lock(&deferred_probe_mutex);
> > if (list_empty(&dev->p->deferred_probe)) {
> > dev_dbg(dev, "Added to deferred list\n");
> > @@ -726,6 +729,7 @@ static int driver_probe_device(struct device_driver *drv, struct device *dev)
> > if (!device_is_registered(dev))
> > return -ENODEV;
> >
> > + dev->can_match = true;
> > pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
> > drv->bus->name, __func__, dev_name(dev), drv->name);
> >
> > @@ -829,6 +833,7 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
> > return 0;
> > } else if (ret == -EPROBE_DEFER) {
> > dev_dbg(dev, "Device match requests probe deferral\n");
> > + dev->can_match = true;
> > driver_deferred_probe_add(dev);
> > } else if (ret < 0) {
> > dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> > @@ -1064,6 +1069,7 @@ static int __driver_attach(struct device *dev, void *data)
> > return 0;
> > } else if (ret == -EPROBE_DEFER) {
> > dev_dbg(dev, "Device match requests probe deferral\n");
> > + dev->can_match = true;
> > driver_deferred_probe_add(dev);
> > } else if (ret < 0) {
> > dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> > diff --git a/include/linux/device.h b/include/linux/device.h
> > index 7619a84f8ce4..1f9cc1ba78bc 100644
> > --- a/include/linux/device.h
> > +++ b/include/linux/device.h
> > @@ -438,6 +438,9 @@ struct dev_links_info {
> > * @state_synced: The hardware state of this device has been synced to match
> > * the software state of this device by calling the driver/bus
> > * sync_state() callback.
> > + * @can_match: The device has matched with a driver at least once or it is in
> > + * a bus (like AMBA) which can't check for matching drivers until
> > + * other devices probe successfully.
> > * @dma_coherent: this particular device is dma coherent, even if the
> > * architecture supports non-coherent devices.
> > * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
> > @@ -544,6 +547,7 @@ struct device {
> > bool offline:1;
> > bool of_node_reused:1;
> > bool state_synced:1;
> > + bool can_match:1;
> > #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
> > defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
> > defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
> > --
On Thu, Feb 18, 2021 at 9:24 AM Saravana Kannan <[email protected]> wrote:
>
> On Thu, Feb 18, 2021 at 9:18 AM Rafael J. Wysocki <[email protected]> wrote:
> >
> > On Thu, Feb 18, 2021 at 12:51 AM Saravana Kannan <[email protected]> wrote:
> > >
> > > There's no point in adding a device to the deferred probe list if we
> > > know for sure that it doesn't have a matching driver. So, check if a
> > > device can match with a driver before adding it to the deferred probe
> > > list.
> >
> > What if a matching driver module loads in the meantime?
>
> Driver registration always triggers a match attempt and this flag will
> get set at that point. Yes, the user can disable autoprobe, but
> that'll block deferred probes too.
>
Btw, this can wait for 5.13. Doesn't need to go into 5.12-rcX.
> > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> > > index 9179825ff646..f18963f42e21 100644
> > > --- a/drivers/base/dd.c
> > > +++ b/drivers/base/dd.c
> > > @@ -123,6 +123,9 @@ static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
> > >
> > > void driver_deferred_probe_add(struct device *dev)
> > > {
> > > + if (!dev->can_match)
> > > + return;
> > > +
Also, if you are worried about this check, for now, I can move it
inside device_links_driver_bound() which is the only place that
currently adds a device to the deferred probe list before the driver
is present. But it seemed like a good check in general to have in
driver_deferred_probe_add(), so I put it there.
-Saravana
Hi Saravana,
On Thu, Feb 18, 2021 at 12:51 AM Saravana Kannan <[email protected]> wrote:
> There's no point in adding a device to the deferred probe list if we
> know for sure that it doesn't have a matching driver. So, check if a
> device can match with a driver before adding it to the deferred probe
> list.
>
> Signed-off-by: Saravana Kannan <[email protected]>
Thanks for your patch!
> ---
> Geert,
>
> Can you give this a shot for your I2C DMA issue with fw_devlink=on?
Yes, this makes I2C use DMA again on Salvator-XS during kernel boot-up.
I haven't run any more elaborate tests on other platforms.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On Tue, Feb 23, 2021 at 2:10 AM Geert Uytterhoeven <[email protected]> wrote:
>
> Hi Saravana,
>
> On Thu, Feb 18, 2021 at 12:51 AM Saravana Kannan <[email protected]> wrote:
> > There's no point in adding a device to the deferred probe list if we
> > know for sure that it doesn't have a matching driver. So, check if a
> > device can match with a driver before adding it to the deferred probe
> > list.
> >
> > Signed-off-by: Saravana Kannan <[email protected]>
>
> Thanks for your patch!
>
> > ---
> > Geert,
> >
> > Can you give this a shot for your I2C DMA issue with fw_devlink=on?
>
> Yes, this makes I2C use DMA again on Salvator-XS during kernel boot-up.
Thanks for testing Geert!
> I haven't run any more elaborate tests on other platforms.
Yeah, this change should only go into 5.13 after it gets tested as
part of driver-core-next.
-Saravana
On Thu, Feb 18, 2021 at 9:24 AM Saravana Kannan <[email protected]> wrote:
>
> On Thu, Feb 18, 2021 at 9:18 AM Rafael J. Wysocki <[email protected]> wrote:
> >
> > On Thu, Feb 18, 2021 at 12:51 AM Saravana Kannan <[email protected]> wrote:
> > >
> > > There's no point in adding a device to the deferred probe list if we
> > > know for sure that it doesn't have a matching driver. So, check if a
> > > device can match with a driver before adding it to the deferred probe
> > > list.
> >
> > What if a matching driver module loads in the meantime?
>
> Driver registration always triggers a match attempt and this flag will
> get set at that point. Yes, the user can disable autoprobe, but
> that'll block deferred probes too.
>
Let me know what you think Rafael.
-Saravana
>
> >
> > >
> > > Signed-off-by: Saravana Kannan <[email protected]>
> > > ---
> > > Geert,
> > >
> > > Can you give this a shot for your I2C DMA issue with fw_devlink=on?
> > >
> > > -Saravana
> > >
> > > drivers/base/dd.c | 6 ++++++
> > > include/linux/device.h | 4 ++++
> > > 2 files changed, 10 insertions(+)
> > >
> > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> > > index 9179825ff646..f18963f42e21 100644
> > > --- a/drivers/base/dd.c
> > > +++ b/drivers/base/dd.c
> > > @@ -123,6 +123,9 @@ static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
> > >
> > > void driver_deferred_probe_add(struct device *dev)
> > > {
> > > + if (!dev->can_match)
> > > + return;
> > > +
> > > mutex_lock(&deferred_probe_mutex);
> > > if (list_empty(&dev->p->deferred_probe)) {
> > > dev_dbg(dev, "Added to deferred list\n");
> > > @@ -726,6 +729,7 @@ static int driver_probe_device(struct device_driver *drv, struct device *dev)
> > > if (!device_is_registered(dev))
> > > return -ENODEV;
> > >
> > > + dev->can_match = true;
> > > pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
> > > drv->bus->name, __func__, dev_name(dev), drv->name);
> > >
> > > @@ -829,6 +833,7 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
> > > return 0;
> > > } else if (ret == -EPROBE_DEFER) {
> > > dev_dbg(dev, "Device match requests probe deferral\n");
> > > + dev->can_match = true;
> > > driver_deferred_probe_add(dev);
> > > } else if (ret < 0) {
> > > dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> > > @@ -1064,6 +1069,7 @@ static int __driver_attach(struct device *dev, void *data)
> > > return 0;
> > > } else if (ret == -EPROBE_DEFER) {
> > > dev_dbg(dev, "Device match requests probe deferral\n");
> > > + dev->can_match = true;
> > > driver_deferred_probe_add(dev);
> > > } else if (ret < 0) {
> > > dev_dbg(dev, "Bus failed to match device: %d\n", ret);
> > > diff --git a/include/linux/device.h b/include/linux/device.h
> > > index 7619a84f8ce4..1f9cc1ba78bc 100644
> > > --- a/include/linux/device.h
> > > +++ b/include/linux/device.h
> > > @@ -438,6 +438,9 @@ struct dev_links_info {
> > > * @state_synced: The hardware state of this device has been synced to match
> > > * the software state of this device by calling the driver/bus
> > > * sync_state() callback.
> > > + * @can_match: The device has matched with a driver at least once or it is in
> > > + * a bus (like AMBA) which can't check for matching drivers until
> > > + * other devices probe successfully.
> > > * @dma_coherent: this particular device is dma coherent, even if the
> > > * architecture supports non-coherent devices.
> > > * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
> > > @@ -544,6 +547,7 @@ struct device {
> > > bool offline:1;
> > > bool of_node_reused:1;
> > > bool state_synced:1;
> > > + bool can_match:1;
> > > #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
> > > defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
> > > defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
> > > --