From: Lukas Wunner <lukas@wunner.de>
To: Heiner Kallweit <hkallweit1@gmail.com>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
linux-pci@vger.kernel.org, "Bjorn Helgaas" <helgaas@kernel.org>,
"Rob Herring" <robh@kernel.org>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Krzysztof Wilczy??ski" <kw@linux.com>,
nic_swsd@realtek.com, "David S. Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@google.com>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 14/17] r8169: Use pcie_lnkctl_clear_and_set() for changing LNKCTL
Date: Thu, 11 May 2023 22:02:44 +0200 [thread overview]
Message-ID: <20230511200244.GA31598@wunner.de> (raw)
In-Reply-To: <98b3b70a-86c0-78c0-b734-0764bb5a21fc@gmail.com>
On Thu, May 11, 2023 at 09:49:52PM +0200, Heiner Kallweit wrote:
> On 11.05.2023 15:14, Ilpo Järvinen wrote:
> > Don't assume that only the driver would be accessing LNKCTL. ASPM
> > policy changes can trigger write to LNKCTL outside of driver's control.
> >
> > Use pcie_lnkctl_clear_and_set() which does proper locking to avoid
> > losing concurrent updates to the register value.
>
> Wouldn't it be more appropriate to add proper locking to the
> underlying pcie_capability_clear_and_set_word()?
PCI config space accessors such as this one are also used in hot paths
(e.g. interrupt handlers). They should be kept lean (and lockless)
by default. We only need locking for specific PCIe Extended Capabilities
which are concurrently accessed by PCI core code and drivers.
Thanks,
Lukas
next prev parent reply other threads:[~2023-05-11 20:02 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-11 13:14 [PATCH 00/17] PCI: Improve LNKCTL & LNKCTL2 concurrency control Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 01/17] PCI: Add concurrency safe clear_and_set variants for LNKCTL{,2} Ilpo Järvinen
2023-05-11 15:55 ` Bjorn Helgaas
2023-05-11 17:35 ` Ilpo Järvinen
2023-05-11 19:22 ` Bjorn Helgaas
2023-05-11 19:58 ` Ilpo Järvinen
2023-05-11 20:07 ` Lukas Wunner
2023-05-11 20:28 ` Ilpo Järvinen
2023-05-11 22:21 ` Bjorn Helgaas
2023-05-11 21:27 ` Bjorn Helgaas
2023-05-11 20:23 ` Lukas Wunner
2023-05-12 8:25 ` Ilpo Järvinen
2023-05-14 10:10 ` Lukas Wunner
2023-05-15 11:59 ` Ilpo Järvinen
2023-05-15 18:28 ` Bjorn Helgaas
2023-05-15 22:12 ` Lukas Wunner
2023-05-11 13:14 ` [PATCH 02/17] PCI: pciehp: Protect LNKCTL changes Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 03/17] PCI/ASPM: Use pcie_lnkctl_clear_and_set() Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 04/17] drm/amdgpu: Use pcie_lnkctl{,2}_clear_and_set() for changing LNKCTL{,2} Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 05/17] drm/radeon: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 06/17] IB/hfi1: " Ilpo Järvinen
2023-05-11 15:19 ` Dean Luick
2023-05-11 20:02 ` Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 07/17] e1000e: Use pcie_lnkctl_clear_and_set() for changing LNKCTL Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 08/17] net/mlx5: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 09/17] wifi: ath9k: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 10/17] mt76: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 11/17] Bluetooth: hci_bcm4377: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 12/17] misc: rtsx: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 13/17] net/tg3: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 14/17] r8169: " Ilpo Järvinen
2023-05-11 19:49 ` Heiner Kallweit
2023-05-11 20:00 ` Ilpo Järvinen
2023-05-11 20:10 ` Lukas Wunner
2023-05-11 20:11 ` Heiner Kallweit
2023-05-11 20:02 ` Lukas Wunner [this message]
2023-05-11 20:17 ` Heiner Kallweit
2023-05-11 13:14 ` [PATCH 15/17] wifi: ath11k: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 16/17] wifi: ath12k: " Ilpo Järvinen
2023-05-11 13:14 ` [PATCH 17/17] wifi: ath10k: " Ilpo Järvinen
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