From: Leon Romanovsky leonro@nvidia.com Sent: Friday, December 4, 2020 6:02 PM
On Fri, Dec 04, 2020 at 12:42:46PM +0100, Greg KH wrote:
On Wed, Dec 02, 2020 at 04:54:24PM -0800, Dan Williams wrote:
From: Dave Ertman david.m.ertman@intel.com
Add support for the Auxiliary Bus, auxiliary_device and auxiliary_driver. It enables drivers to create an auxiliary_device and bind an auxiliary_driver to it.
The bus supports probe/remove shutdown and suspend/resume
callbacks.
Each auxiliary_device has a unique string based id; driver binds to an auxiliary_device based on this id through the bus.
Co-developed-by: Kiran Patil kiran.patil@intel.com Co-developed-by: Ranjani Sridharan ranjani.sridharan@linux.intel.com Co-developed-by: Fred Oh fred.oh@linux.intel.com Co-developed-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Kiran Patil kiran.patil@intel.com Signed-off-by: Ranjani Sridharan ranjani.sridharan@linux.intel.com Signed-off-by: Fred Oh fred.oh@linux.intel.com Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Dave Ertman david.m.ertman@intel.com Reviewed-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Shiraz Saleem shiraz.saleem@intel.com Reviewed-by: Parav Pandit parav@mellanox.com Reviewed-by: Dan Williams dan.j.williams@intel.com Reviewed-by: Martin Habets mhabets@solarflare.com Link: https://lore.kernel.org/r/20201113161859.1775473-2-david.m.ertman@in tel.com Signed-off-by: Dan Williams dan.j.williams@intel.com
This patch is "To:" the maintainers that have a pending backlog of driver updates dependent on this facility, and "Cc:" Greg. Greg, I understand you have asked for more time to fully review this and apply it to driver-core.git, likely for v5.12, but please consider Acking it for v5.11 instead. It looks good to me and several other
stakeholders.
Namely, stakeholders that have pressure building up behind this facility in particular Mellanox RDMA, but also SOF, Intel Ethernet, and later on Compute Express Link.
I will take the blame for the 2 months of silence that made this awkward to take through driver-core.git, but at the same time I do not want to see that communication mistake inconvenience other parties that reasonably thought this was shaping up to land in v5.11.
I am willing to host this version at:
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/linux tags/auxiliary-bus-for-5.11
...for all the independent drivers to have a common commit baseline. It is not there yet pending Greg's Ack.
For example implementations incorporating this patch, see Dave Ertman's SOF series:
https://lore.kernel.org/r/20201113161859.1775473-2-david.m.ertman@in tel.com
...and Leon's mlx5 series:
http://lore.kernel.org/r/20201026111849.1035786-1-leon@kernel.org
PS: Greg I know I promised some review on newcomer patches to help with your queue, unfortunately Intel-internal review is keeping my plate full. Again, I do not want other stakeholder to be waiting on me to resolve that backlog.
Ok, I spent some hours today playing around with this. I wrote up a small test-patch for this (how did anyone test this thing???).
We are running all verifications tests that we have over our mlx5 driver. It includes devices reloads, power failures, FW reconfiguration to emulate different devices with and without error injections and many more. Up till now, no new bugs that are not known to us were found.
Subfunction patchset [1] that is using auxiliary bus in mlx5 driver is also been used by verification and performance tests.
[1] https://lore.kernel.org/linux-rdma/20201112192424.2742-1-parav@nvidia.com/