From: Sinan Kaya <okaya@codeaurora.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Ondrej Zary <linux@rainbow-software.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Bjorn Helgaas <bhelgaas@google.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
Linux PCI <linux-pci@vger.kernel.org>,
wim@djo.tudelft.nl, ravikanth.nalla@hpe.com
Subject: Re: 4.7 regression: ACPI: No IRQ available for PCI Interrupt Link [LNKD]. Try pci=noacpi or acpi=off
Date: Fri, 30 Sep 2016 17:33:51 -0400 [thread overview]
Message-ID: <230f80d3-b7f0-6b33-5176-5de568576f48@codeaurora.org> (raw)
In-Reply-To: <CAJZ5v0gKFVEYFhyge8+_ZTSg_OK6uzBByivgbvEV-Up4Q3YSiw@mail.gmail.com>
On 9/30/2016 5:27 PM, Rafael J. Wysocki wrote:
> On Fri, Sep 30, 2016 at 11:14 PM, Sinan Kaya <okaya@codeaurora.org> wrote:
>> On 9/30/2016 5:04 PM, Rafael J. Wysocki wrote:
>>>>>
>>>>> I hope it makes sense now. I tend to skip details sometimes. Feel free to
>>>>> send more questions.
>>> Thanks for the information!
>>>
>>> IIUC, basically, what you are proposing would be to restore the old
>>> penalizing method for IRQs in the 0-255 range and use the new approach
>>> for the rest, right?
>>
>> Correct.
>>
>>>
>>> What's the drawback, if any?
>>
>> I don't see any drawback to be honest.
>
> I'd go for it then, if Bjorn doesn't hate it.
OK. I'll prep something.
Bjorn?
>
>> The reason why I got rid of these ISA
>> API functions was to remove some of the x86ism from ACPI code. This was Bjorn's
>> request to clean it up and we failed in two places so far.
>>
>> 1. acpi_irq_penalty_init
>> 2. acpi_penalize_sci_irq
>>
>> and we ended up reverting both of these changes. The reverts are all because of the
>> fact that these APIs are called asynchronously without any coordination with the
>> PCI Link object or the interrupt controller driver about when it is a good time to be
>> called.
>>
>> During this debug, I learnt that acpi_penalize_isa_irq gets called before even ACPI
>> gets to initialize and relies on static IRQ array for keeping the penalties.
>
> So maybe add some comments to that code to explain why things are
> arranged the way they are. We may need/want to revisit it at one
> point and such comments will be very useful then.
Yeah, I think this code definitely needs some documentation. It ended up being
one of the most fragile places in the kernel. This is my 3rd attempt to rearrange
the code.
>
> Thanks,
> Rafael
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
next prev parent reply other threads:[~2016-09-30 21:34 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-25 13:12 Ondrej Zary
2016-09-26 12:23 ` Rafael J. Wysocki
2016-09-27 21:02 ` Ondrej Zary
2016-09-27 21:32 ` Rafael J. Wysocki
2016-09-27 22:23 ` Ondrej Zary
2016-09-27 22:58 ` Rafael J. Wysocki
2016-09-27 23:06 ` Sinan Kaya
2016-09-28 8:32 ` Ondrej Zary
2016-09-28 14:11 ` Sinan Kaya
2016-09-28 17:02 ` Ondrej Zary
2016-09-28 18:22 ` Sinan Kaya
2016-09-28 19:23 ` Ondrej Zary
2016-09-28 23:38 ` Sinan Kaya
2016-09-29 9:10 ` Ondrej Zary
2016-09-29 13:09 ` okaya
2016-09-29 13:49 ` Ondrej Zary
2016-09-29 14:28 ` Sinan Kaya
2016-09-29 14:35 ` Sinan Kaya
2016-09-29 16:48 ` Ondrej Zary
2016-09-29 17:18 ` Sinan Kaya
2016-09-29 18:00 ` Ondrej Zary
2016-09-29 22:39 ` Sinan Kaya
2016-09-30 6:44 ` Ondrej Zary
2016-09-30 13:14 ` okaya
2016-09-30 15:56 ` Ondrej Zary
2016-09-30 19:30 ` Sinan Kaya
2016-09-30 19:39 ` Rafael J. Wysocki
2016-09-30 20:24 ` Sinan Kaya
2016-09-30 21:04 ` Rafael J. Wysocki
2016-09-30 21:14 ` Sinan Kaya
2016-09-30 21:27 ` Rafael J. Wysocki
2016-09-30 21:33 ` Sinan Kaya [this message]
2016-10-01 17:49 ` Sinan Kaya
2016-10-02 16:53 ` Ondrej Zary
2016-10-03 1:05 ` Sinan Kaya
2016-10-03 7:25 ` Ondrej Zary
2016-10-04 14:30 ` Sinan Kaya
2016-10-04 17:54 ` Ondrej Zary
2016-09-29 14:18 ` Wim Osterholt
2016-09-29 14:31 ` Sinan Kaya
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=230f80d3-b7f0-6b33-5176-5de568576f48@codeaurora.org \
--to=okaya@codeaurora.org \
--cc=bhelgaas@google.com \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux@rainbow-software.org \
--cc=rafael@kernel.org \
--cc=ravikanth.nalla@hpe.com \
--cc=rjw@rjwysocki.net \
--cc=wim@djo.tudelft.nl \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®