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Thangaraj Samynathan 7e1c28fbf2
spi: spi-pci1xxxx: enable concurrent DMA read/write across SPI transfers
Refactor the pci1xxxx SPI driver to allow overlapping DMA read and
write operations across SPI transfers. This improves throughput and
reduces idle time between SPI transactions.

Transfer sequence:
- Start with a DMA read to load TX data from host to device buffer.
- After DMA read completes, trigger the SPI transfer.
- On SPI completion:
  - Start DMA write to copy received data from RX buffer to host.
  - Start the next DMA read to prepare TX data for the following transfer.
- Begin the next SPI transfer after both DMA write and read complete.

To implement this sequence, the following changes were made:
- Added dma_completion_count to track and synchronize DMA completions.
- Split DMA setup into separate functions for TX (read) and RX (write).
- Introduced separate spinlocks for safe access to RD and WR DMA registers.

This new flow enables efficient pipelining by overlapping data
preparation and completion stages, leading to better SPI transfer
performance and utilization of DMA engines.

Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
Link: https://patch.msgid.link/20250630073233.7356-1-thangaraj.s@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2025-06-30 12:15:45 +01:00
arch - Make sure the array tracking which kernel text positions need to be 2025-06-22 10:30:44 -07:00
block block-6.16-20250614 2025-06-14 09:25:22 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: ahash - Fix infinite recursion in ahash_def_finup 2025-06-18 17:02:02 +08:00
Documentation spi: dt-bindings: add nxp,lpc3220-spi.yaml 2025-06-27 00:29:18 +01:00
drivers spi: spi-pci1xxxx: enable concurrent DMA read/write across SPI transfers 2025-06-30 12:15:45 +01:00
fs - Make sure the array tracking which kernel text positions need to be 2025-06-22 10:30:44 -07:00
include Add devm_dma_request_chan() to simplify probe 2025-06-27 12:07:07 +01:00
init init: fix build warnings about export.h 2025-06-11 22:42:36 -07:00
io_uring io_uring-6.16-20250621 2025-06-21 08:40:45 -07:00
ipc - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
kernel - Fix missing prototypes warnings 2025-06-22 10:17:51 -07:00
lib This push fixes a regression in ahash (broken fallback finup) 2025-06-19 23:15:10 -07:00
LICENSES LICENSES: add CC0-1.0 license text 2025-05-21 14:54:17 +02:00
mm * Further fixups for ITS mitigation 2025-06-16 11:36:21 -07:00
net nfsd-6.16 fixes: 2025-06-21 09:20:15 -07:00
rust Driver core fixes for 6.16-rc3 2025-06-18 14:31:16 -07:00
samples - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
scripts gendwarfksyms: Fix structure type overrides 2025-06-16 00:49:48 +09:00
security selinux: fix selinux_xfrm_alloc_user() to set correct ctx_len 2025-06-16 19:02:22 -04:00
sound ALSA: hda/realtek: Enable headset Mic on Positivo P15X 2025-06-20 10:05:46 +02:00
tools - Make sure the switch to the global hash is requested always under a lock so 2025-06-22 10:09:23 -07:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge branch 'kvm-lockdep-common' into HEAD 2025-05-28 06:29:17 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: ignore Python compiled bytecode 2025-04-24 10:12:46 -06:00
.mailmap Including fixes from wireless. The ath12k fix to avoid FW crashes 2025-06-19 10:21:32 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Update Christoph's Email address and make it consistent 2025-05-12 23:50:31 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS gpio fixes for v6.16-rc3 2025-06-20 10:07:56 -07:00
Makefile Linux 6.16-rc3 2025-06-22 13:30:08 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.