Message-ID: <05bc8f6e-b0cc-2ae6-db7a-ad90b3e69778@i2se.com>
Date:   Sun, 5 Mar 2023 16:00:29 +0100
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Subject: Re: [PATCH v1] serdev: Set fwnode for serdev devices
To:     Florian Fainelli <f.fainelli@gmail.com>,
        Saravana Kannan <saravanak@google.com>
Cc:     Rob Herring <robh@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>, kernel-team@android.com,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
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From:   Stefan Wahren <stefan.wahren@i2se.com>
In-Reply-To: <667f007f-1cb0-7e89-242a-c41823e82bee@gmail.com>
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Precedence: bulk

Hi,

Am 03.03.23 um 18:22 schrieb 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@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.
>
> 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.

okay, this is fine. From my point of view this is not necessary to test 
built-in.

I tested latest mainline with Raspberry Pi 4 (multi_v7_defconfig + 
ARM_LPAE) and there is no regression:

Tested-by: Stefan Wahren <stefan.wahren@i2se.com>

Thanks