mirror of
https://github.com/armbian/linux-cix.git
synced 2026-01-06 12:30:45 -08:00
347654387b
[ Upstream commit ebefac5647968679f6ef5803e5d35a71997d20fa ] We initially introduced a quick fix limiting the queue depth to 1 as experimentation showed that it fixed data corruption on 64GB steamdecks. Further experimentation revealed corruption only happens when the last PRP data element aligns to the end of the page boundary. The device appears to treat this as a PRP chain to a new list instead of the data element that it actually is. This implementation is in violation of the spec. Encountering this errata with the Linux driver requires the host request a 128k transfer and coincidently be handed the last small pool dma buffer within a page. The QD1 quirk effectly works around this because the last data PRP always was at a 248 byte offset from the page start, so it never appeared at the end of the page, but comes at the expense of throttling IO and wasting the remainder of the PRP page beyond 256 bytes. Also to note, the MDTS on these devices is small enough that the "large" prp pool can hold enough PRP elements to never reach the end, so that pool is not a problem either. Introduce a new quirk to ensure the small pool is always aligned such that the last PRP element can't appear a the end of the page. This comes at the expense of wasting 256 bytes per small pool page allocated. Link: https://lore.kernel.org/linux-nvme/20241113043151.GA20077@lst.de/T/#u Fixes: 83bdfcbdbe5d ("nvme-pci: qdepth 1 quirk") Cc: Paweł Anikiel <panikiel@google.com> Signed-off-by: Robert Beckett <bob.beckett@collabora.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.