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

[Florian Fainelli]

On 3/3/23 03:57, Stefan Wahren wrote:
> 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@xxxxxxxx> 
> > > 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@xxxxxxxxx>
> > > > > Link: 
> > > > > https://lore.kernel.org/lkml/03b70a8a-0591-f28b-a567-9d2f736f17e5@xxxxxxxxx/
> > > > > Cc: Stefan Wahren <stefan.wahren@xxxxxxxx>
> > > > > Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
> > > >
> > > > 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.

My configuration uses hci_uart as a module, and it would always load 
fine, but I suppose I can make sure that even built-in this works 
properly. Give me a day or two to test that.
--
Florian