Re: [PATCH] mmc: meson-gx: remove IRQF_ONESHOT

From: Jerome Brunet
Date: Wed Oct 07 2020 - 07:33:00 EST



On Tue 06 Oct 2020 at 17:33, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> Brad,
>
> On Wed, Oct 07 2020 at 00:45, Brad Harper wrote:
>> I'm happy to test anything on a range of amlogic hardware with standard
>> / rt and multiple mmc devices. Ill test Jerome's patch in next 24
>> hours to report the results.
>
> please do not top-post and trim your replies.
>
>> On 6/10/2020 11:43 pm, Thomas Gleixner wrote:
>>> We rather should make interrupts which need to have their primary
>>> handler in hard interrupt context to set IRQF_NO_THREAD. That
>>> should at the same time confirm that the primary handler is RT
>>> safe.
>>>
>>> Let me stare at the core code and the actual usage sites some more.
>
> So there are a few nasties in there and I faintly remember that there
> was an assumption that interrupts which are requested with both a
> primary and a secondary handler should quiesce the device interrupt in
> the primary handler if needed. OTOH, this also enforces that the primary
> handler is RT safe, which is after a quick scan of all the usage sites
> not a given and quite some of the users rely on IRQF_ONESHOT.
>
> The below untested patch should cure the problem and keep the interrupt
> line masked if requested with IRQF_ONESHOT.
>

With arm64 defconfig on Khadas vim3, no obvious regression. Looks good.

Tested-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>

I did not test with RT. Brad, Could you let us know is Thomas's patch
works for you ? Thx