Instantiated SPI device nodes are marked with OF_POPULATE. This was
introduced in bd6c164. On unloading, loaded device nodes will of course
be unmarked. The problem are nodes the fail during initialisation: If a
node failed during registration, it won't be unloaded and hence never be
unmarked again.
So if a SPI driver module is unloaded and reloaded, it will skip nodes
that failed before.
Skip device nodes that are already populated and mark them only in case
of success.
Fixes: bd6c164 ("spi: Mark instantiated device nodes with OF_POPULATE")
Signed-off-by: Ralf Ramsauer <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
---
Hi,
imagine the following situation: you loaded a spi driver as module, but
it fails to instantiate, because of some reasons (e.g. some resources,
like gpios, might be in use in userspace).
When reloading the driver, _all_ nodes, including previously failed
ones, should be probed again. This is not the case at the moment.
Current behaviour only re-registers nodes that were previously
successfully loaded.
This small patches fixes this behaviour. I stumbled over this while
working on a spi driver.
Ralf
drivers/spi/spi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 200ca22..f96a04e 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1604,12 +1604,15 @@ static void of_register_spi_devices(struct spi_master *master)
return;
for_each_available_child_of_node(master->dev.of_node, nc) {
- if (of_node_test_and_set_flag(nc, OF_POPULATED))
+ if (of_node_check_flag(nc, OF_POPULATED))
continue;
spi = of_register_spi_device(master, nc);
- if (IS_ERR(spi))
+ if (IS_ERR(spi)) {
dev_warn(&master->dev, "Failed to create SPI device for %s\n",
nc->full_name);
+ continue;
+ }
+ of_node_set_flag(nc, OF_POPULATED);
}
}
#else
--
2.10.1
Hi Ralf,
(Cc i2c)
On Fri, Oct 14, 2016 at 9:31 PM, Ralf Ramsauer
<[email protected]> wrote:
> Instantiated SPI device nodes are marked with OF_POPULATE. This was
> introduced in bd6c164. On unloading, loaded device nodes will of course
> be unmarked. The problem are nodes the fail during initialisation: If a
> node failed during registration, it won't be unloaded and hence never be
> unmarked again.
>
> So if a SPI driver module is unloaded and reloaded, it will skip nodes
> that failed before.
>
> Skip device nodes that are already populated and mark them only in case
> of success.
>
> Fixes: bd6c164 ("spi: Mark instantiated device nodes with OF_POPULATE")
> Signed-off-by: Ralf Ramsauer <[email protected]>
> Cc: Geert Uytterhoeven <[email protected]>
> ---
> Hi,
>
> imagine the following situation: you loaded a spi driver as module, but
> it fails to instantiate, because of some reasons (e.g. some resources,
> like gpios, might be in use in userspace).
>
> When reloading the driver, _all_ nodes, including previously failed
> ones, should be probed again. This is not the case at the moment.
> Current behaviour only re-registers nodes that were previously
> successfully loaded.
>
> This small patches fixes this behaviour. I stumbled over this while
> working on a spi driver.
Thanks for your patch!
> drivers/spi/spi.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 200ca22..f96a04e 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -1604,12 +1604,15 @@ static void of_register_spi_devices(struct spi_master *master)
> return;
>
> for_each_available_child_of_node(master->dev.of_node, nc) {
> - if (of_node_test_and_set_flag(nc, OF_POPULATED))
> + if (of_node_check_flag(nc, OF_POPULATED))
> continue;
> spi = of_register_spi_device(master, nc);
> - if (IS_ERR(spi))
> + if (IS_ERR(spi)) {
> dev_warn(&master->dev, "Failed to create SPI device for %s\n",
> nc->full_name);
> + continue;
> + }
> + of_node_set_flag(nc, OF_POPULATED);
I think it's safer to keep the atomic test-and-set, but clear the flag on
failure, cfr. of_platform_device_create_pdata() and of_amba_device_create().
Shouldn't of_spi_notify() be fixed, too?
The same issue exists for i2c in of_i2c_register_devices() and of_i2c_notify(),
which is what I had used as an example.
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 Sun, Oct 16, 2016 at 10:49:11AM +0200, Geert Uytterhoeven wrote:
> Hi Ralf,
>
> (Cc i2c)
Thanks for letting me know! Adding Pantelis to CC, as he is the original
author of OF_DYNAMIC. Please keep me in the loop.
>
> On Fri, Oct 14, 2016 at 9:31 PM, Ralf Ramsauer
> <[email protected]> wrote:
> > Instantiated SPI device nodes are marked with OF_POPULATE. This was
> > introduced in bd6c164. On unloading, loaded device nodes will of course
> > be unmarked. The problem are nodes the fail during initialisation: If a
> > node failed during registration, it won't be unloaded and hence never be
> > unmarked again.
> >
> > So if a SPI driver module is unloaded and reloaded, it will skip nodes
> > that failed before.
> >
> > Skip device nodes that are already populated and mark them only in case
> > of success.
> >
> > Fixes: bd6c164 ("spi: Mark instantiated device nodes with OF_POPULATE")
> > Signed-off-by: Ralf Ramsauer <[email protected]>
> > Cc: Geert Uytterhoeven <[email protected]>
> > ---
> > Hi,
> >
> > imagine the following situation: you loaded a spi driver as module, but
> > it fails to instantiate, because of some reasons (e.g. some resources,
> > like gpios, might be in use in userspace).
> >
> > When reloading the driver, _all_ nodes, including previously failed
> > ones, should be probed again. This is not the case at the moment.
> > Current behaviour only re-registers nodes that were previously
> > successfully loaded.
> >
> > This small patches fixes this behaviour. I stumbled over this while
> > working on a spi driver.
>
> Thanks for your patch!
>
> > drivers/spi/spi.c | 7 +++++--
> > 1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> > index 200ca22..f96a04e 100644
> > --- a/drivers/spi/spi.c
> > +++ b/drivers/spi/spi.c
> > @@ -1604,12 +1604,15 @@ static void of_register_spi_devices(struct spi_master *master)
> > return;
> >
> > for_each_available_child_of_node(master->dev.of_node, nc) {
> > - if (of_node_test_and_set_flag(nc, OF_POPULATED))
> > + if (of_node_check_flag(nc, OF_POPULATED))
> > continue;
> > spi = of_register_spi_device(master, nc);
> > - if (IS_ERR(spi))
> > + if (IS_ERR(spi)) {
> > dev_warn(&master->dev, "Failed to create SPI device for %s\n",
> > nc->full_name);
> > + continue;
> > + }
> > + of_node_set_flag(nc, OF_POPULATED);
>
> I think it's safer to keep the atomic test-and-set, but clear the flag on
> failure, cfr. of_platform_device_create_pdata() and of_amba_device_create().
>
> Shouldn't of_spi_notify() be fixed, too?
>
> The same issue exists for i2c in of_i2c_register_devices() and of_i2c_notify(),
> which is what I had used as an example.
>
> 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
Hi Geert,
On 10/16/2016 10:49 AM, Geert Uytterhoeven wrote:
> Hi Ralf,
>
> (Cc i2c)
>
> On Fri, Oct 14, 2016 at 9:31 PM, Ralf Ramsauer
> <[email protected]> wrote:
>> Instantiated SPI device nodes are marked with OF_POPULATE. This was
>> introduced in bd6c164. On unloading, loaded device nodes will of course
>> be unmarked. The problem are nodes the fail during initialisation: If a
>> node failed during registration, it won't be unloaded and hence never be
>> unmarked again.
>>
>> So if a SPI driver module is unloaded and reloaded, it will skip nodes
>> that failed before.
>>
>> Skip device nodes that are already populated and mark them only in case
>> of success.
>>
>> Fixes: bd6c164 ("spi: Mark instantiated device nodes with OF_POPULATE")
>> Signed-off-by: Ralf Ramsauer <[email protected]>
>> Cc: Geert Uytterhoeven <[email protected]>
>> ---
>> Hi,
>>
>> imagine the following situation: you loaded a spi driver as module, but
>> it fails to instantiate, because of some reasons (e.g. some resources,
>> like gpios, might be in use in userspace).
>>
>> When reloading the driver, _all_ nodes, including previously failed
>> ones, should be probed again. This is not the case at the moment.
>> Current behaviour only re-registers nodes that were previously
>> successfully loaded.
>>
>> This small patches fixes this behaviour. I stumbled over this while
>> working on a spi driver.
>
> Thanks for your patch!
>
>> drivers/spi/spi.c | 7 +++++--
>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
>> index 200ca22..f96a04e 100644
>> --- a/drivers/spi/spi.c
>> +++ b/drivers/spi/spi.c
>> @@ -1604,12 +1604,15 @@ static void of_register_spi_devices(struct spi_master *master)
>> return;
>>
>> for_each_available_child_of_node(master->dev.of_node, nc) {
>> - if (of_node_test_and_set_flag(nc, OF_POPULATED))
>> + if (of_node_check_flag(nc, OF_POPULATED))
>> continue;
>> spi = of_register_spi_device(master, nc);
>> - if (IS_ERR(spi))
>> + if (IS_ERR(spi)) {
>> dev_warn(&master->dev, "Failed to create SPI device for %s\n",
>> nc->full_name);
>> + continue;
>> + }
>> + of_node_set_flag(nc, OF_POPULATED);
>
> I think it's safer to keep the atomic test-and-set, but clear the flag on
> failure, cfr. of_platform_device_create_pdata() and of_amba_device_create().
Ack, no prob. Let me change this in the next version.
>
> Shouldn't of_spi_notify() be fixed, too?
Right, that's almost the same path.
>
> The same issue exists for i2c in of_i2c_register_devices() and of_i2c_notify(),
> which is what I had used as an example.
Good old c&p ;-)
I'll fix and test that tomorrow and come back with two patches, as it
touches different subsystems.
Best
Ralf
>
> 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
>
--
Ralf Ramsauer
GPG: 0x8F10049B
Hi Ralf,
> On Oct 16, 2016, at 12:55 , Ralf Ramsauer <[email protected]> wrote:
>
> Hi Geert,
>
> On 10/16/2016 10:49 AM, Geert Uytterhoeven wrote:
>> Hi Ralf,
>>
>> (Cc i2c)
>>
>> On Fri, Oct 14, 2016 at 9:31 PM, Ralf Ramsauer
>> <[email protected]> wrote:
>>> Instantiated SPI device nodes are marked with OF_POPULATE. This was
>>> introduced in bd6c164. On unloading, loaded device nodes will of course
>>> be unmarked. The problem are nodes the fail during initialisation: If a
>>> node failed during registration, it won't be unloaded and hence never be
>>> unmarked again.
>>>
>>> So if a SPI driver module is unloaded and reloaded, it will skip nodes
>>> that failed before.
>>>
>>> Skip device nodes that are already populated and mark them only in case
>>> of success.
>>>
>>> Fixes: bd6c164 ("spi: Mark instantiated device nodes with OF_POPULATE")
>>> Signed-off-by: Ralf Ramsauer <[email protected]>
>>> Cc: Geert Uytterhoeven <[email protected]>
>>> ---
>>> Hi,
>>>
>>> imagine the following situation: you loaded a spi driver as module, but
>>> it fails to instantiate, because of some reasons (e.g. some resources,
>>> like gpios, might be in use in userspace).
>>>
>>> When reloading the driver, _all_ nodes, including previously failed
>>> ones, should be probed again. This is not the case at the moment.
>>> Current behaviour only re-registers nodes that were previously
>>> successfully loaded.
>>>
>>> This small patches fixes this behaviour. I stumbled over this while
>>> working on a spi driver.
>>
>> Thanks for your patch!
>>
>>> drivers/spi/spi.c | 7 +++++--
>>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
>>> index 200ca22..f96a04e 100644
>>> --- a/drivers/spi/spi.c
>>> +++ b/drivers/spi/spi.c
>>> @@ -1604,12 +1604,15 @@ static void of_register_spi_devices(struct spi_master *master)
>>> return;
>>>
>>> for_each_available_child_of_node(master->dev.of_node, nc) {
>>> - if (of_node_test_and_set_flag(nc, OF_POPULATED))
>>> + if (of_node_check_flag(nc, OF_POPULATED))
>>> continue;
>>> spi = of_register_spi_device(master, nc);
>>> - if (IS_ERR(spi))
>>> + if (IS_ERR(spi)) {
>>> dev_warn(&master->dev, "Failed to create SPI device for %s\n",
>>> nc->full_name);
>>> + continue;
>>> + }
>>> + of_node_set_flag(nc, OF_POPULATED);
>>
>> I think it's safer to keep the atomic test-and-set, but clear the flag on
>> failure, cfr. of_platform_device_create_pdata() and of_amba_device_create().
> Ack, no prob. Let me change this in the next version.
>>
>> Shouldn't of_spi_notify() be fixed, too?
> Right, that's almost the same path.
>>
>> The same issue exists for i2c in of_i2c_register_devices() and of_i2c_notify(),
>> which is what I had used as an example.
> Good old c&p ;-)
> I'll fix and test that tomorrow and come back with two patches, as it
> touches different subsystems.
>
Thanks for this. This is a very rare case that’s easy to slip through.
It is good to be consistent :)
> Best
> Ralf
>>
Regards
— Pantelis
>> 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
>>
>
>
> --
> Ralf Ramsauer
> GPG: 0x8F10049B
On Mon, Oct 17, 2016 at 10:20:47PM +0300, Pantelis Antoniou wrote:
> Hi Ralf,
>
> > On Oct 16, 2016, at 12:55 , Ralf Ramsauer <[email protected]> wrote:
> >
> > Hi Geert,
> >
> > On 10/16/2016 10:49 AM, Geert Uytterhoeven wrote:
> >> Hi Ralf,
> >>
> >> (Cc i2c)
> >>
> >> On Fri, Oct 14, 2016 at 9:31 PM, Ralf Ramsauer
> >> <[email protected]> wrote:
> >>> Instantiated SPI device nodes are marked with OF_POPULATE. This was
> >>> introduced in bd6c164. On unloading, loaded device nodes will of course
> >>> be unmarked. The problem are nodes the fail during initialisation: If a
> >>> node failed during registration, it won't be unloaded and hence never be
> >>> unmarked again.
> >>>
> >>> So if a SPI driver module is unloaded and reloaded, it will skip nodes
> >>> that failed before.
> >>>
> >>> Skip device nodes that are already populated and mark them only in case
> >>> of success.
> >>>
> >>> Fixes: bd6c164 ("spi: Mark instantiated device nodes with OF_POPULATE")
> >>> Signed-off-by: Ralf Ramsauer <[email protected]>
> >>> Cc: Geert Uytterhoeven <[email protected]>
> >>> ---
> >>> Hi,
> >>>
> >>> imagine the following situation: you loaded a spi driver as module, but
> >>> it fails to instantiate, because of some reasons (e.g. some resources,
> >>> like gpios, might be in use in userspace).
> >>>
> >>> When reloading the driver, _all_ nodes, including previously failed
> >>> ones, should be probed again. This is not the case at the moment.
> >>> Current behaviour only re-registers nodes that were previously
> >>> successfully loaded.
> >>>
> >>> This small patches fixes this behaviour. I stumbled over this while
> >>> working on a spi driver.
> >>
> >> Thanks for your patch!
> >>
> >>> drivers/spi/spi.c | 7 +++++--
> >>> 1 file changed, 5 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> >>> index 200ca22..f96a04e 100644
> >>> --- a/drivers/spi/spi.c
> >>> +++ b/drivers/spi/spi.c
> >>> @@ -1604,12 +1604,15 @@ static void of_register_spi_devices(struct spi_master *master)
> >>> return;
> >>>
> >>> for_each_available_child_of_node(master->dev.of_node, nc) {
> >>> - if (of_node_test_and_set_flag(nc, OF_POPULATED))
> >>> + if (of_node_check_flag(nc, OF_POPULATED))
> >>> continue;
> >>> spi = of_register_spi_device(master, nc);
> >>> - if (IS_ERR(spi))
> >>> + if (IS_ERR(spi)) {
> >>> dev_warn(&master->dev, "Failed to create SPI device for %s\n",
> >>> nc->full_name);
> >>> + continue;
> >>> + }
> >>> + of_node_set_flag(nc, OF_POPULATED);
> >>
> >> I think it's safer to keep the atomic test-and-set, but clear the flag on
> >> failure, cfr. of_platform_device_create_pdata() and of_amba_device_create().
> > Ack, no prob. Let me change this in the next version.
> >>
> Thanks for this. This is a very rare case that’s easy to slip through.
> It is good to be consistent :)
I read this as acked-by for the series?
> > Thanks for this. This is a very rare case that’s easy to slip through.
> > It is good to be consistent :)
>
> I read this as acked-by for the series?
Ah, I mixed up. You acked V2 :)