From: Enric Balletbo i Serra <enric.balletbo@collabora.com>
To: Marc Zyngier <maz@kernel.org>, Saravana Kannan <saravanak@google.com>
Cc: Frank Wunderlich <wichtig@fw-web.de>,
LKML <linux-kernel@vger.kernel.org>,
Collabora Kernel ML <kernel@collabora.com>,
Frank Wunderlich <linux@fw-web.de>,
Matthias Brugger <matthias.bgg@gmail.com>,
Nicolas Boichat <drinkcat@chromium.org>,
Hsin-Yi Wang <hsinyi@chromium.org>,
Hanks Chen <hanks.chen@mediatek.com>,
Jason Cooper <jason@lakedaemon.net>,
Thomas Gleixner <tglx@linutronix.de>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
"moderated list:ARM/Mediatek SoC support"
<linux-mediatek@lists.infradead.org>
Subject: Re: [PATCH] Revert "irqchip/mtk-sysirq: Convert to a platform driver"
Date: Fri, 21 Aug 2020 11:20:29 +0200 [thread overview]
Message-ID: <95ae0ae3-7798-d6d5-fc37-391862a0b4ca@collabora.com> (raw)
In-Reply-To: <14b8f4b9667d29ee25e25eb19c69e3f7@kernel.org>
Hi Marc,
On 20/8/20 16:53, Marc Zyngier wrote:
> On 2020-08-20 09:07, Saravana Kannan wrote:
>> On Thu, Aug 20, 2020 at 12:56 AM Marc Zyngier <maz@kernel.org> wrote:
>>>
>>> On 2020-08-19 19:51, Saravana Kannan wrote:
>>> > On Wed, Aug 19, 2020 at 9:52 AM Frank Wunderlich <wichtig@fw-web.de>
>>> > wrote:
>>> >>
>>> >> hi,
>>> >>
>>> >> does the fix you've linked to my revert [1] not work in your case?
>>> >>
>>> >> [1] https://patchwork.kernel.org/patch/11718481/
>>> >
>>> > Thanks for pointing it out Frank. Also, might want to avoid top
>>> > posting in the future.
>>> >
>>> > Enric, Can you please try that other fix and see if that solves your
>>> > issue?
>>>
>>> I think Enric was clear that the driver does probe correctly
>>> (meaning that he has the fix in his tree). It is everything else
>>> that breaks, because none of the drivers on the platform are
>>> equipped to defer their own probing.
>>>
>>> I think we need to change this works right now, meaning that we can't
>>> blindly change the behaviour of *built-in* drivers. I'll see if I can
>>> come up with something quickly, but I'll otherwise take Enric patch.
>>
>> Sounds fair Marc.
>>
>> Btw, Enric, out of curiosity, can you try adding "fw_devlink=on" to
>> your kernel command line to see if it helps? It basically ensures
>> proper probe ordering without depending on the drivers. There are some
>> corner cases where it still can't work properly (too much to explain
>> for a late night email), but if the platforms don't have those corner
>> cases it'll work perfectly.
>>
>> I'm fine with the revert if Marc isn't able to find a quick fix to the
>> drivers, but this might also fix your problem right away.
>
> I'm afraid there is no quick fix if we want to preserve the current
> behavior with built-in drivers, and not having "fw_devlink=on" by
> default makes it irrelevant for most people.
>
> fw_devlink also prevents my test platforms from booting (my rk3399
> doesn't find its PCI devices with it), while the same kernel boots
> just fine without it. It could well be that the corner case is
> likely to be more prevalent than you seem to expect.
>
> I will probably end-up end-up queuing reverts for both mtk-sysirq,
> mtk-cirq, and qcom-pdc (the first two can't be built as module with
> mainline anyway, and I seem to remember that the latter caused some
> controversy as well).
>
> As an experiment, I have pushed out a branch[1] that implements
> a "hybrid" probe, retaining the previous early probe mechanism when
> the driver is built-in, and letting things rip when built as a
> module (if you do that, you hopefully know what you are doing).
> I'd welcome some testing on affected platforms (I don't have
> anything I can run mainline on that'd be affected).
>
Unfortunately, my Kukui (MT8183) board doesn't boot at all with those patches. I
only did a quick test and I didn't dig further, please let me know if you want I
debug more the issue. IMHO, right now, the revert seems to be the better
solution for this cycle.
Thanks,
Enric
> Thanks,
>
> M.
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=irq/hybrid-probe
>
next prev parent reply other threads:[~2020-08-21 9:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-19 16:19 [PATCH] Revert "irqchip/mtk-sysirq: Convert to a platform driver" Enric Balletbo i Serra
[not found] ` <C9E59107-CE83-4554-9447-5DE5BEE09A3B@fw-web.de>
2020-08-19 18:51 ` Saravana Kannan
2020-08-20 7:56 ` Marc Zyngier
2020-08-20 8:07 ` Saravana Kannan
2020-08-20 14:53 ` Marc Zyngier
2020-08-20 19:39 ` Saravana Kannan
2020-08-21 9:20 ` Enric Balletbo i Serra [this message]
2020-08-21 10:17 ` Marc Zyngier
2020-08-21 14:03 ` Frank Wunderlich
2020-08-25 23:40 ` [tip: irq/urgent] irqchip: Revert modular support for drivers using IRQCHIP_PLATFORM_DRIVER helperse tip-bot2 for Marc Zyngier
-- strict thread matches above, loose matches on Subject: below --
2020-08-17 14:57 [PATCH] Revert "irqchip/mtk-sysirq: Convert to a platform driver" Frank Wunderlich
2020-08-17 15:04 ` Enric Balletbo Serra
2020-08-21 14:07 ` Frank Wunderlich
2020-08-17 15:27 ` Marc Zyngier
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