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qiuguorui1 47c8387a96 irqchip/stm32-exti: Avoid losing interrupts due to clearing pending bits by mistake
commit e579076ac0a3bebb440fab101aef3c42c9f4c709 upstream.

In the current code, when the eoi callback of the exti clears the pending
bit of the current interrupt, it will first read the values of fpr and
rpr, then logically OR the corresponding bit of the interrupt number,
and finally write back to fpr and rpr.

We found through experiments that if two exti interrupts,
we call them int1/int2, arrive almost at the same time. in our scenario,
the time difference is 30 microseconds, assuming int1 is triggered first.

there will be an extreme scenario: both int's pending bit are set to 1,
the irq handle of int1 is executed first, and eoi handle is then executed,
at this moment, all pending bits are cleared, but the int 2 has not
finally been reported to the cpu yet, which eventually lost int2.

According to stm32's TRM description about rpr and fpr: Writing a 1 to this
bit will trigger a rising edge event on event x, Writing 0 has no
effect.

Therefore, when clearing the pending bit, we only need to clear the
pending bit of the irq.

Fixes: 927abfc446 ("irqchip/stm32: Add stm32mp1 support with hierarchy domain")
Signed-off-by: qiuguorui1 <qiuguorui1@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org # v4.18+
Link: https://lore.kernel.org/r/20200820031629.15582-1-qiuguorui1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:27:06 +02:00
Documentation kbuild: support LLVM=1 to switch the default tools to Clang/LLVM 2020-08-26 10:40:47 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch powerpc/perf: Fix crashes with generic_compat_pmu & BHRB 2020-09-03 11:27:05 +02:00
block blk-mq: order adding requests to hctx->dispatch and checking SCHED_RESTART 2020-09-03 11:27:01 +02:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto crypto: af_alg - Work around empty control messages without MSG_MORE 2020-09-03 11:27:05 +02:00
drivers irqchip/stm32-exti: Avoid losing interrupts due to clearing pending bits by mistake 2020-09-03 11:27:06 +02:00
fs writeback: Fix sync livelock due to b_dirty_time processing 2020-09-03 11:27:04 +02:00
include writeback: Fix sync livelock due to b_dirty_time processing 2020-09-03 11:27:04 +02:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel genirq/matrix: Deal with the sillyness of for_each_cpu() on UP 2020-09-03 11:27:06 +02:00
lib test_kmod: avoid potential double free in trigger_config_run_type() 2020-08-21 13:05:37 +02:00
mm mm/vunmap: add cond_resched() in vunmap_pmd_range 2020-09-03 11:26:52 +02:00
net can: j1939: transport: j1939_xtp_rx_dat_one(): compare own packets to detect corruptions 2020-09-03 11:26:58 +02:00
samples bpf: Fix fds_example SIGSEGV error 2020-08-19 08:16:03 +02:00
scripts kconfig: qconf: fix signal connection to invalid slots 2020-08-26 10:41:04 +02:00
security Smack: prevent underflow in smk_set_cipso() 2020-08-19 08:16:16 +02:00
sound ASoC: wm8994: Avoid attempts to read unreadable registers 2020-09-03 11:26:59 +02:00
tools selftests: disable rp_filter for icmp_redirect.sh 2020-09-03 11:26:59 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set 2020-08-26 10:41:08 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.61 2020-08-26 10:41:08 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.