RE: [PATCH v5 06/11] drm/radeon: Use RMW accessors for changing LNKCTL

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

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On Fri, 18 Aug 2023, Deucher, Alexander wrote:

> [Public]
> 
> > -----Original Message-----
> > From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> > Sent: Monday, July 17, 2023 8:05 AM
> > To: linux-pci@vger.kernel.org; Bjorn Helgaas <bhelgaas@google.com>; Lorenzo
> > Pieralisi <lorenzo.pieralisi@arm.com>; Rob Herring <robh@kernel.org>;
> > Krzysztof Wilczyński <kw@linux.com>; Emmanuel Grumbach
> > <emmanuel.grumbach@intel.com>; Rafael J . Wysocki <rafael@kernel.org>;
> > Heiner Kallweit <hkallweit1@gmail.com>; Lukas Wunner <lukas@wunner.de>;
> > Andy Shevchenko <andriy.shevchenko@linux.intel.com>; Deucher, Alexander
> > <Alexander.Deucher@amd.com>; Koenig, Christian
> > <Christian.Koenig@amd.com>; Pan, Xinhui <Xinhui.Pan@amd.com>; David
> > Airlie <airlied@gmail.com>; Daniel Vetter <daniel@ffwll.ch>; amd-
> > gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; linux-
> > kernel@vger.kernel.org
> > Cc: Dean Luick <dean.luick@cornelisnetworks.com>; Jonas Dreßler
> > <verdre@v0yd.nl>; Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>;
> > stable@vger.kernel.org
> > Subject: [PATCH v5 06/11] drm/radeon: Use RMW accessors for changing
> > LNKCTL
> >
> > Don't assume that only the driver would be accessing LNKCTL. ASPM policy
> > changes can trigger write to LNKCTL outside of driver's control.
> > And in the case of upstream bridge, the driver does not even own the device
> > it's changing the registers for.
> >
> > Use RMW capability accessors which do proper locking to avoid losing
> > concurrent updates to the register value.
> >
> > Fixes: 8a7cd27679d0 ("drm/radeon/cik: add support for pcie gen1/2/3
> > switching")
> > Fixes: b9d305dfb66c ("drm/radeon: implement pcie gen2/3 support for SI")
> > Suggested-by: Lukas Wunner <lukas@wunner.de>
> > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> > Cc: stable@vger.kernel.org
> 
> For this and the amdgpu patch:
> Acked-by: Alex Deucher <alexander.deucher@amd.com>
> I'm not sure if this is stable material however.  Is there some issue today?

These were added without Cc stable into pci.git/pcie-rmw.

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