From: Manivannan Sadhasivam <mani@kernel.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: linux-pci@vger.kernel.org,
Christian Zigotzky <chzigotzky@xenosoft.de>,
mad skateman <madskateman@gmail.com>,
"R . T . Dickinson" <rtd2@xtra.co.nz>,
Darren Stevens <darren@stevens-zone.net>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Lukas Wunner <lukas@wunner.de>,
luigi burdo <intermediadc@hotmail.com>, Al <al@datazap.net>,
Roland <rol7and@gmx.com>, Hongxing Zhu <hongxing.zhu@nxp.com>,
hypexed@yahoo.com.au, linuxppc-dev@lists.ozlabs.org,
debian-powerpc@lists.debian.org, linux-kernel@vger.kernel.org,
Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH 2/2] PCI/ASPM: Avoid L0s and L1 on Freescale Root Ports
Date: Fri, 7 Nov 2025 11:39:50 +0530 [thread overview]
Message-ID: <ogkty663ld7fe3qmbxyil47pudidenqeikol5prk7n3qexpteq@h77qi3sg5xo4> (raw)
In-Reply-To: <20251106183643.1963801-3-helgaas@kernel.org>
On Thu, Nov 06, 2025 at 12:36:39PM -0600, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
>
> Christian reported that f3ac2ff14834 ("PCI/ASPM: Enable all ClockPM and
> ASPM states for devicetree platforms") broke booting on the A-EON X5000.
>
> Fixes: f3ac2ff14834 ("PCI/ASPM: Enable all ClockPM and ASPM states for devicetree platforms")
> Fixes: df5192d9bb0e ("PCI/ASPM: Enable only L0s and L1 for devicetree platforms"
> )
> Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
> Link: https://lore.kernel.org/r/db5c95a1-cf3e-46f9-8045-a1b04908051a@xenosoft.de
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
> drivers/pci/quirks.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 214ed060ca1b..44e780718953 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2525,6 +2525,18 @@ static void quirk_disable_aspm_l0s_l1(struct pci_dev *dev)
> */
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ASMEDIA, 0x1080, quirk_disable_aspm_l0s_l1);
>
> +/*
> + * Remove ASPM L0s and L1 support from cached copy of Link Capabilities so
> + * aspm.c won't try to enable them.
> + */
> +static void quirk_disable_aspm_l0s_l1_cap(struct pci_dev *dev)
> +{
> + dev->lnkcap &= ~PCI_EXP_LNKCAP_ASPM_L0S;
> + dev->lnkcap &= ~PCI_EXP_LNKCAP_ASPM_L1;
> + pci_info(dev, "ASPM: L0s L1 removed from Link Capabilities to work around device defect\n");
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_FREESCALE, 0x0451, quirk_disable_aspm_l0s_l1_cap);
From the commit message of the earlier version [1] you shared:
Removing advertised features prevents aspm.c from enabling them, even if
users try to enable them via sysfs or by building the kernel with
CONFIG_PCIEASPM_POWERSAVE or CONFIG_PCIEASPM_POWER_SUPERSAVE.
Going by this reasoning, shouldn't we be doing this for the other quirks
(quirk_disable_aspm_l0s_l1/quirk_disable_aspm_l0s) as well?
- Mani
[1] https://lore.kernel.org/linux-pci/20251105220925.GA1926619@bhelgaas
--
மணிவண்ணன் சதாசிவம்
next prev parent reply other threads:[~2025-11-07 6:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-06 18:36 [PATCH 0/2] PCI/ASPM: Allow quirks to avoid L0s and L1 Bjorn Helgaas
2025-11-06 18:36 ` [PATCH 1/2] PCI/ASPM: Cache Link Capabilities so quirks can override them Bjorn Helgaas
2025-11-07 1:17 ` Shawn Lin
2025-11-07 6:03 ` Manivannan Sadhasivam
2025-11-07 6:16 ` Shawn Lin
2025-11-07 5:32 ` Lukas Wunner
2025-11-07 15:25 ` Bjorn Helgaas
2025-11-06 18:36 ` [PATCH 2/2] PCI/ASPM: Avoid L0s and L1 on Freescale Root Ports Bjorn Helgaas
2025-11-07 5:35 ` Lukas Wunner
2025-11-07 6:09 ` Manivannan Sadhasivam [this message]
2025-11-07 21:55 ` Bjorn Helgaas
2025-11-06 23:45 ` [PATCH 0/2] PCI/ASPM: Allow quirks to avoid L0s and L1 Bjorn Helgaas
2025-11-07 2:33 ` Hongxing Zhu
2025-11-07 5:40 ` Manivannan Sadhasivam
2025-11-07 6:33 ` Lukas Wunner
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=ogkty663ld7fe3qmbxyil47pudidenqeikol5prk7n3qexpteq@h77qi3sg5xo4 \
--to=mani@kernel.org \
--cc=al@datazap.net \
--cc=bhelgaas@google.com \
--cc=chzigotzky@xenosoft.de \
--cc=darren@stevens-zone.net \
--cc=debian-powerpc@lists.debian.org \
--cc=glaubitz@physik.fu-berlin.de \
--cc=helgaas@kernel.org \
--cc=hongxing.zhu@nxp.com \
--cc=hypexed@yahoo.com.au \
--cc=intermediadc@hotmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=lukas@wunner.de \
--cc=madskateman@gmail.com \
--cc=rol7and@gmx.com \
--cc=rtd2@xtra.co.nz \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).