From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794281794; b=GOOORaBehIsq66TVK40VKlZ0qFhzm4sokdG4C1t8Ex8sVnRqYmkosuDBvj+tasFUxGsK Pd03mWumJbZz+WcGUgI5Rz9v2qsdRoycpPL7VVlw5fpOoTcQq3WZebt4YEb9JEOKD98i/ wokTeDSBuJvoWtNzrrpS/L3QZgDbffTbqHHcWauig8uSES8SFPfZd/G0WBaQGN3wbizaz PuvoGb3e7755cUjyTTsACKwLxr9H1p5PIa+wgXzv1+qUtDA+zHt22Q0dKk5RqRflTbe8x wI/PU047iQaVx76HKTnRt9D7EQVtJS/qak87EMNWPw+uyBMYcLLPbyzOf2nYgcpHX8Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794281794; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=fcPFTiQXzvhXH/OHGrDr/VboUqPj177Njh5i67Q+qME=; b=db1BrtFFr0KYOGlQMa182SfKvC47J1IapjYoCkIx9I04co3zZx8yOJtZp1SBwgi6pSqD wzzfKieYYoIsJu80ZKbrRdAiFqYCsGL82a/e4xXrCy/gc+LGdh80kuQHH7rXV4Ckt1cQM 4DsFS3yQyw3Bnh+qvHaurdUyoneTlkoAoYFpz1m6ZjICIKTtbCaSK1fasGFQ+aaAx4tg7 rkAUKOWcPnC4FGJgLNx+aY6rUgQ33DYDos6Hd4kJu5flIakB4fxdov6sBaWfupL+IRNqz 739CXM9tqv8UBofBp7yfQeMYIyXQsQdo12jQjVRigh5GEaAX7cYJTBts1NlKsjGXRFQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bNyD2Lvk; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 42828606A31C for ; Tue, 10 Nov 2026 03:36:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bNyD2Lvk Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFD131F008BF; Tue, 10 Nov 2026 03:36:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794281793; bh=fcPFTiQXzvhXH/OHGrDr/VboUqPj177Njh5i67Q+qME=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=bNyD2LvkoBS/twtBdduHlZSwWflw2ndsjhxdYdTu0w9NJ85qV66QY6eXZrPncXfOH 7cWMJPzBgdA1Ssqnj9PntpZNFk3TzFq0yAWAYN2eYYcsJv/4i572bEDy+LC6AVWxfN burYco77mob7oVtoBoMut7+brrkzn/4Kpa8eHdfYYWmEKvFgkv6Mh4X7bP0Y3i2LnH plaRPkvwXzPRhNdAo9f/BykmNdeAwSXTBx/Dsp0tikTAZBZ5wXl3/423KZz7HJh8Q3 4VD+NqhcffG8tL94qv0lYsiPA6/Q6w/GWSDZD7z4F8mvycIXSrPEmEWEc2pvcWkve0 9L9irnqJWHY8A== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v9 06/11] serial: 8250_dw: derive RX trigger thresholds from the FIFO depth Reply-To: sashiko-reviews@lists.linux.dev To: "James Hilliard" Cc: linux-serial@vger.kernel.org In-Reply-To: <20261109-submit-h616-uart-fifo-v1-v9-6-3f03961dae8a@gmail.com> References: <20261109-submit-h616-uart-fifo-v1-v9-0-3f03961dae8a@gmail.com> <20261109-submit-h616-uart-fifo-v1-v9-6-3f03961dae8a@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 10 Nov 2026 03:36:33 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > DW_apb_uart uses receive thresholds of one byte, one quarter full, > one half full and two bytes below full. The generic 16550A table describes > these encodings only for a 16-byte FIFO. For example, the half-full setti= ng > on a 64-byte DW FIFO is reported as eight bytes instead of 32, and a sysfs > request for 32 bytes selects the 62-byte encoding. >=20 > Build a per-port threshold table from the discovered FIFO depth in dwlib > and install receive-trigger callbacks for CPR-described FIFOs, including > LPSS ports. Keep the setup helper available to integrations which obtain > the depth without probing the optional DW registers. Validate that each > threshold is positive and representable before constructing the table. >=20 > Serialize FCR updates with termios and the port lock, acquire a runtime PM > reference before accessing the device, and propagate resume errors without > changing the shadow or hardware. Update only the trigger field so changing > the threshold preserves the FIFO contents. >=20 > The FCR mapping is documented in the DW_apb_uart databook, section 6, > FIFO Control Register. The existing default FCR encoding is unchanged. >=20 > Signed-off-by: James Hilliard Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261109-submit-h61= 6-uart-fifo-v1-v9-0-3f03961dae8a@gmail.com?part=3D6