From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: bhelgaas@google.com, koba.ko@canonical.com,
sathyanarayanan.kuppuswamy@linux.intel.com,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] PCI: Add helper to check if any of ancestor device support D3cold
Date: Thu, 24 Aug 2023 14:56:56 +0300 [thread overview]
Message-ID: <20230824115656.GW3465@black.fi.intel.com> (raw)
In-Reply-To: <20230824044645.423378-1-kai.heng.feng@canonical.com>
Hi,
On Thu, Aug 24, 2023 at 12:46:43PM +0800, Kai-Heng Feng wrote:
> In addition to nearest upstream bridge, driver may want to know if the
> entire hierarchy can be powered off to perform different action.
>
> So walk higher up the hierarchy to find out if any device has valid
> _PR3.
I'm not entirely sure this is good idea. The drivers should expect that
the power will be turned off pretty soon after device enters D3hot. Also
_PR3 is not PCI concept it's ACPI concept so API like this would only
work on systems with ACPI.
next prev parent reply other threads:[~2023-08-24 11:58 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-24 4:46 [PATCH 1/3] PCI: Add helper to check if any of ancestor device support D3cold Kai-Heng Feng
2023-08-24 4:46 ` [PATCH 2/3] PCI/AER: Disable AER service on suspend Kai-Heng Feng
2023-08-24 4:46 ` [PATCH 3/3] PCI/DPC: Disable DPC " Kai-Heng Feng
2023-08-24 11:56 ` Mika Westerberg [this message]
2023-08-24 13:46 ` [PATCH 1/3] PCI: Add helper to check if any of ancestor device support D3cold Kai-Heng Feng
2023-08-25 5:29 ` Mika Westerberg
2023-08-25 5:43 ` Kai-Heng Feng
2023-08-25 6:39 ` Mika Westerberg
2023-08-26 13:11 ` Bjorn Helgaas
2023-08-28 7:29 ` Kai-Heng Feng
2023-08-28 16:23 ` Bjorn Helgaas
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