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Marek Vasut ef690e3f62 rsi: Move card interrupt handling to RX thread
[ Upstream commit 287431463e ]

The interrupt handling of the RS911x is particularly heavy. For each RX
packet, the card does three SDIO transactions, one to read interrupt
status register, one to RX buffer length, one to read the RX packet(s).
This translates to ~330 uS per one cycle of interrupt handler. In case
there is more incoming traffic, this will be more.

The drivers/mmc/core/sdio_irq.c has the following comment, quote "Just
like traditional hard IRQ handlers, we expect SDIO IRQ handlers to be
quick and to the point, so that the holding of the host lock does not
cover too much work that doesn't require that lock to be held."

The RS911x interrupt handler does not fit that. This patch therefore
changes it such that the entire IRQ handler is moved to the RX thread
instead, and the interrupt handler only wakes the RX thread.

This is OK, because the interrupt handler only does things which can
also be done in the RX thread, that is, it checks for firmware loading
error(s), it checks buffer status, it checks whether a packet arrived
and if so, reads out the packet and passes it to network stack.

Moreover, this change permits removal of a code which allocated an
skbuff only to get 4-byte-aligned buffer, read up to 8kiB of data
into the skbuff, queue this skbuff into local private queue, then in
RX thread, this buffer is dequeued, the data in the skbuff as passed
to the RSI driver core, and the skbuff is deallocated. All this is
replaced by directly calling the RSI driver core with local buffer.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Angus Ainslie <angus@akkea.ca>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Martin Kepplinger <martink@posteo.de>
Cc: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Cc: Siva Rebbagondla <siva8118@gmail.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201103180941.443528-1-marex@denx.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-07 12:34:08 +01:00
arch riscv: Get rid of MAX_EARLY_MAPPING_SIZE 2021-03-07 12:34:05 +01:00
block blk-settings: align max_sectors on "logical_block_size" boundary 2021-03-04 11:38:22 +01:00
certs certs: Fix blacklist flag type confusion 2021-03-04 11:37:59 +01:00
crypto crypto: michael_mic - fix broken misalignment handling 2021-03-04 11:38:31 +01:00
Documentation dt-bindings: net: btusb: DT fix s/interrupt-name/interrupt-names/ 2021-03-07 12:34:08 +01:00
drivers rsi: Move card interrupt handling to RX thread 2021-03-07 12:34:08 +01:00
fs xfs: Fix assert failure in xfs_setattr_size() 2021-03-07 12:34:05 +01:00
include net: fix dev_ifsioc_locked() race condition 2021-03-07 12:34:07 +01:00
init kgdb: fix to kill breakpoints on initmem after boot 2021-03-04 11:38:46 +01:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel sched/core: Allow try_invoke_on_locked_down_task() with irqs disabled 2021-03-07 12:34:04 +01:00
lib udp: fix skb_copy_and_csum_datagram with odd segment sizes 2021-02-17 11:02:28 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm/hugetlb.c: fix unnecessary address expansion of pmd sharing 2021-03-07 12:34:06 +01:00
net net: fix dev_ifsioc_locked() race condition 2021-03-07 12:34:07 +01:00
samples watch_queue: Drop references to /dev/watch_queue 2021-03-04 11:37:59 +01:00
scripts scripts/recordmcount.pl: support big endian for ARCH sh 2021-02-26 10:13:02 +01:00
security tomoyo: ignore data race while checking quota 2021-03-07 12:34:05 +01:00
sound ASoC: qcom: Remove useless debug print 2021-03-07 12:34:08 +01:00
tools wireguard: selftests: test multiple parallel streams 2021-03-04 11:38:47 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() 2021-02-26 10:13:01 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-10 15:30:13 -08:00
Makefile Linux 5.10.20 2021-03-04 11:38:47 +01:00
README

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.