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[180.34.120.7]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-b71268bdb2dsm4641759a12.5.2025.10.26.05.55.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Oct 2025 05:55:25 -0700 (PDT) From: FUJITA Tomonori To: a.hindborg@kernel.org, alex.gaynor@gmail.com, aliceryhl@google.com, dakr@kernel.org, daniel.almeida@collabora.com, ojeda@kernel.org Cc: anna-maria@linutronix.de, bjorn3_gh@protonmail.com, boqun.feng@gmail.com, frederic@kernel.org, gary@garyguo.net, jstultz@google.com, linux-kernel@vger.kernel.org, lossin@kernel.org, lyude@redhat.com, rust-for-linux@vger.kernel.org, sboyd@kernel.org, tglx@linutronix.de, tmgross@umich.edu Subject: [PATCH v3 0/2] Add read_poll_timeout_atomic support Date: Sun, 26 Oct 2025 21:54:56 +0900 Message-ID: <20251026125458.2772103-1-fujita.tomonori@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add read_poll_timeout_atomic function which polls periodically until a condition is met, an error occurs, or the attempt limit is reached. This helper is used to wait for a condition in atomic context, mirroring the C's read_poll_timeout_atomic(). In atomic context, the timekeeping infrastructure is unavailable, so reliable time-based timeouts cannot be implemented. So instead, the helper accepts a maximum number of attempts and busy-waits (udelay + cpu_relax) between tries. v2: https://lore.kernel.org/lkml/20251021071146.2357069-1-fujita.tomonori@gmail.com/ - revert the function name - simplify the example code - add debug_assert to check the range for udelay v1: https://lore.kernel.org/lkml/20250821035710.3692455-1-fujita.tomonori@gmail.com/ - use the attempt limit instead of timeout - rename the function to read_poll_count_atomic - add the comment about C's udelay behavior. FUJITA Tomonori (2): rust: add udelay() function rust: Add read_poll_timeout_atomic function rust/helpers/time.c | 5 +++ rust/kernel/io/poll.rs | 72 ++++++++++++++++++++++++++++++++++++++- rust/kernel/time/delay.rs | 39 +++++++++++++++++++++ 3 files changed, 115 insertions(+), 1 deletion(-) base-commit: 26c1a20bf7ce76e9afe4030f25bec20e3c63dcf8 -- 2.43.0