From: Vidya Sagar <vidyas@nvidia.com>
To: Lorenzo Pieralisi <lpieralisi@kernel.org>,
Bjorn Helgaas <helgaas@kernel.org>
Cc: Jon Hunter <jonathanh@nvidia.com>,
Jingoo Han <jingoohan1@gmail.com>,
Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
Krzysztof Wilczynski <kw@linux.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Thierry Reding <treding@nvidia.com>,
PCI <linux-pci@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Krishna Thota <kthota@nvidia.com>,
Manikanta Maddireddy <mmaddireddy@nvidia.com>,
sagar.tv@gmail.com,
Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
Rob Herring <robh@kernel.org>
Subject: Re: [PATCH V1] PCI: dwc: Use dev_info for PCIe link down event logging
Date: Mon, 3 Oct 2022 16:55:16 +0530 [thread overview]
Message-ID: <27e8f2e8-8b97-a142-9da4-437c8dd498c4@nvidia.com> (raw)
In-Reply-To: <75b9bbc0-0e99-3201-f83d-f1fe28c54b12@nvidia.com>
Hi Bjorn / Lorenzo,
Just checking if there are any more comments for this patch? If not, are
we good to take it?
Thanks,
Vidya Sagar
On 9/26/2022 3:59 PM, Vidya Sagar wrote:
> Hi,
> Just checking if we are good with this patch or does it need any further
> modifications?
>
> Thanks,
> Vidya Sagar
>
> On 9/15/2022 8:22 PM, Manivannan Sadhasivam wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> On Thu, Sep 15, 2022 at 09:16:27AM -0500, Rob Herring wrote:
>>> On Wed, Sep 14, 2022 at 1:24 AM Manivannan Sadhasivam
>>> <manivannan.sadhasivam@linaro.org> wrote:
>>>>
>>>> On Tue, Sep 13, 2022 at 03:07:46PM -0500, Bjorn Helgaas wrote:
>>>>> On Tue, Sep 13, 2022 at 06:00:30PM +0100, Jon Hunter wrote:
>>>>>> On 13/09/2022 17:51, Manivannan Sadhasivam wrote:
>>>>>>> On Tue, Sep 13, 2022 at 03:42:37PM +0530, Vidya Sagar wrote:
>>>>>>>> Some of the platforms (like Tegra194 and Tegra234) have open
>>>>>>>> slots and
>>>>>>>> not having an endpoint connected to the slot is not an error.
>>>>>>>> So, changing the macro from dev_err to dev_info to log the event.
>>>>>>>
>>>>>>> But the link up not happening is an actual error and -ETIMEDOUT
>>>>>>> is being
>>>>>>> returned. So I don't think the log severity should be changed.
>>>>>>
>>>>>> Yes it is an error in the sense it is a timeout, but reporting an
>>>>>> error
>>>>>> because nothing is attached to a PCI slot seems a bit noisy.
>>>>>> Please note
>>>>>> that a similar change was made by the following commit and it also
>>>>>> seems
>>>>>> appropriate here ...
>>>>>>
>>>>>> commit 4b16a8227907118e011fb396022da671a52b2272
>>>>>> Author: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>>>>>> Date: Tue Jun 18 23:32:06 2019 +0530
>>>>>>
>>>>>> PCI: tegra: Change link retry log level to debug
>>>>>>
>>>>>>
>>>>>> BTW, we check for error messages in the dmesg output and this is a
>>>>>> new error
>>>>>> seen as of Linux v6.0 and so this was flagged in a test. We can
>>>>>> ignore the
>>>>>> error, but in this case it seem more appropriate to make this a
>>>>>> info or
>>>>>> debug level print.
>>>>>
>>>>> Can you tell whether there's a device present, e.g., via Slot Status
>>>>> Presence Detect? If there's nothing in the slot, I don't know why we
>>>>> would print anything at all. If a card is present but there's no
>>>>> link, that's probably worthy of dev_info() or even dev_err().
>>>>>
>>>>
>>>> I don't think all form factors allow for the PRSNT pin to be wired up,
>>>> so we cannot know if the device is actually present in the slot or
>>>> not all
>>>> the time. Maybe we should do if the form factor supports it?
>>>>
>>>>> I guess if you can tell the slot is empty, there's no point in even
>>>>> trying to start the link, so you could avoid both the message and the
>>>>> timeout by not even calling dw_pcie_wait_for_link().
>>>>
>>>> Right. There is an overhead of waiting for ~1ms during boot.
>>>
>>> Async probe should mitigate that, right? Saravana is working toward
>>> making that the default instead of opt in, but you could opt in now.
>>>
>>
>> No. The delay is due to the DWC core waiting for link up that depends on
>> the PCIe device to be present on the slot. The driver probe order
>> doesn't apply here.
>>
>> Thanks,
>> Mani
>>
>>> Rob
next prev parent reply other threads:[~2022-10-03 11:25 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-13 10:12 [PATCH V1] PCI: dwc: Use dev_info for PCIe link down event logging Vidya Sagar
2022-09-13 16:51 ` Manivannan Sadhasivam
2022-09-13 17:00 ` Jon Hunter
2022-09-13 20:07 ` Bjorn Helgaas
2022-09-14 6:24 ` Manivannan Sadhasivam
2022-09-14 11:02 ` Vidya Sagar
2022-09-14 11:18 ` Manivannan Sadhasivam
2022-09-14 11:25 ` Jon Hunter
2022-09-14 11:43 ` Manivannan Sadhasivam
2022-09-14 11:52 ` Jon Hunter
2022-09-14 12:44 ` Krzysztof Wilczyński
2022-09-14 13:45 ` Manivannan Sadhasivam
2022-09-14 14:52 ` Krzysztof Wilczyński
2022-09-14 15:11 ` Jon Hunter
2022-09-15 14:16 ` Rob Herring
2022-09-15 14:52 ` Manivannan Sadhasivam
2022-09-26 10:29 ` Vidya Sagar
2022-10-03 11:25 ` Vidya Sagar [this message]
2022-10-04 12:53 ` Rob Herring
2022-10-10 6:02 ` Vidya Sagar
2022-10-26 18:06 ` Rob Herring
2022-10-27 9:39 ` Lorenzo Pieralisi
2022-10-27 11:03 ` Manivannan Sadhasivam
2022-09-14 6:12 ` Manivannan Sadhasivam
2022-09-15 10:44 ` Manivannan Sadhasivam
2022-10-18 6:21 ` Jon Hunter
2022-10-18 16:43 ` Bjorn Helgaas
2022-10-26 11:39 ` Jon Hunter
2022-10-26 12:33 ` Lorenzo Pieralisi
2022-10-27 9:55 ` Ben Dooks
2022-10-27 11:05 ` Manivannan Sadhasivam
2022-11-10 15:40 ` Lorenzo Pieralisi
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=27e8f2e8-8b97-a142-9da4-437c8dd498c4@nvidia.com \
--to=vidyas@nvidia.com \
--cc=bhelgaas@google.com \
--cc=gustavo.pimentel@synopsys.com \
--cc=helgaas@kernel.org \
--cc=jingoohan1@gmail.com \
--cc=jonathanh@nvidia.com \
--cc=kthota@nvidia.com \
--cc=kw@linux.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=lpieralisi@kernel.org \
--cc=manivannan.sadhasivam@linaro.org \
--cc=mmaddireddy@nvidia.com \
--cc=robh@kernel.org \
--cc=sagar.tv@gmail.com \
--cc=treding@nvidia.com \
/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;
as well as URLs for NNTP newsgroup(s).