Re: [PATCH v1] serdev: Set fwnode for serdev devices

[Stefan Wahren <stefan.wahren@i2se.com>]

Hi,

Am 02.03.23 um 18:51 schrieb Florian Fainelli:
>
>
> On 3/2/2023 9:20 AM, Saravana Kannan wrote:
>> On Thu, Mar 2, 2023 at 9:01 AM Stefan Wahren <stefan.wahren@i2se.com> 
>> wrote:
>>>
>>> Hi Saravana,
>>>
>>> Am 02.03.23 um 03:35 schrieb Saravana Kannan:
>>>> This allow fw_devlink to do dependency tracking for serdev devices.
>>>>
>>>> Reported-by: Florian Fainelli <f.fainelli@gmail.com>
>>>> Link: 
>>>> https://lore.kernel.org/lkml/03b70a8a-0591-f28b-a567-9d2f736f17e5@gmail.com/
>>>> Cc: Stefan Wahren <stefan.wahren@i2se.com>
>>>> Signed-off-by: Saravana Kannan <saravanak@google.com>
>>>
>>> since this fixes an issue on Raspberry Pi 4, shouldn't this be 
>>> mentioned
>>> in the commit message and providing a Fixes tag?
>>
>> So RPi 4 was never creating a device links between serdev devices and
>> their consumers. The error message was just a new one I added and we
>> are noticing and catching the fact that serdev wasn't setting fwnode
>> for a device.
>>
>> I'm also not sure if I can say this commit "Fixes" an issue in serdev
>> core because when serdev core was written, fw_devlink wasn't a thing.
>> Once I add Fixes, people will start pulling this into stable
>> branches/other trees where I don't think this should be pulled into
>> older stable branches.
>
> That is kind of the point of Fixes: tag, is not it? It is appropriate 
> to list a commit that is not specific to serdev, but maybe a 
> particular point into the fw_devlink history. Given this did not 
> appear to have a functional impact, we could go without one.

i was under the impression that this issue breaks at least Bluetooth on 
Raspberry Pi 4 because the driver is never probed. I cannot see the 
success output in Florian's trace. Something like this:

[    7.124879] hci_uart_bcm serial0-0: supply vbat not found, using 
dummy regulator
[    7.131743] hci_uart_bcm serial0-0: supply vddio not found, using 
dummy regulator
...
[    7.517249] Bluetooth: hci0: BCM: chip id 107
[    7.517499] Bluetooth: hci0: BCM: features 0x2f
[    7.519757] Bluetooth: hci0: BCM4345C0
[    7.519768] Bluetooth: hci0: BCM4345C0 (003.001.025) build 0000
[    7.539495] Bluetooth: hci0: BCM4345C0 'brcm/BCM4345C0.hcd' Patch
...
[    8.348831] Bluetooth: hci0: BCM43455 37.4MHz Raspberry Pi 3+
[    8.348845] Bluetooth: hci0: BCM4345C0 (003.001.025) build 0342

I just want to make sure that 6.2 doesn't have a regression.