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=1794698861; b=gu8GmIxuYPYBdyjxIQ0aNwLn6014xQnhtrqe5aD3VqosUf932/wofUbpSx1ihvTo8LYX edGIoS73ukHo5I+rwUp5EAwN7OV5Lol8Sg/FO5KrgjZjoBm61Id9N/F0gsK8J3qciDkTf jZ2Ca7dQF7Z0u8HGOOCSz+6LF0l+hZEF/4L+GCry9Qd4nV9O96oZRTXhPPqLIYFC10Mri m+bYeESlD6FK8oi5m9ejKrbgLSZuifetM/FJVqttbhcnJGaP1pObgLnakzeegKIvqKDiL TGBtJYx85w0c57z8HCyCh2eiG7SZ+ghaVZBkRipP5xDbNTfQtkBWgD3EQDTg55e0Q5w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794698861; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=f0CCnxWIOusi0hK8KTQlmItCqtzYpeq6Z+p5ovZps98=; b=DkoCzRFO8JnGvjnf3427jYqTOwjdok0DyNq8YJBJdNYJDMl7q3LvABKUn3kqnALBnKQr H5/P3y9SxUj1eRwpbzZz7Wd0mHolbkrRtgeZhpq7ykN5Ns230HXi4jyCkFHlDMhkEBdOy 0CRfJAj+7w8rGRPfJoGRtYshs7Wb1dzz16NBTxSJjqWUT/zJEro1yGwqQc9YK+Y5auLaC elwvYHEe1/poLFMhaQPrAq2pZoFB/wkT7mvh2pgqb+k/Pg3gghmMgqMrLzv80jwgRBEt4 VenoL2R/F6b5kJUhp1obF2vg0AZlh7n5BwuOm84WCPr+qh67esNvTG7yBhN7OPkZfxA== 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=LmD9JCtG; 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 1D4C4606A323 for ; Sat, 14 Nov 2026 23:27:40 +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=LmD9JCtG Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93D721F000C4; Sat, 14 Nov 2026 23:27:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794698860; bh=f0CCnxWIOusi0hK8KTQlmItCqtzYpeq6Z+p5ovZps98=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=LmD9JCtGunWyfVTy0cn6kM9HdQfVbqYVlr4Aj892AKIeu7mt8c+C4SCWex9pe6crZ jCbxX6GaS3KbaTOa5hg4egYmeIOLqk0ISRUuQaFbUN+dPuLO9tHEQ5+ujMYotFcVDb gP3voE6D1Vycws52+iczYq+isYJyyOGt3IPwDxT1RP4PqRQp6/SqLuS+wM3HCxonTD sEXIHKfsceZOn+/EscE21JnymxAnccKCos28H1H4PNSMO0u6+xJKEJbYfKXvc+jmYO 6uQhRKndcelHkivrxd903dYuq3OqMZWs14ddtmCYWanBwDBhXUkOShEMiPB830jHEf j4wk5t4yTtbgQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 11/16] HID: ft260: workaround for TN_189 errata endpoint STALL after enumeration Reply-To: sashiko-reviews@lists.linux.dev To: "Michael Zaidman" Cc: linux-serial@vger.kernel.org In-Reply-To: <20261114230800.1344401-12-michael.zaidman@gmail.com> References: <20261114230800.1344401-1-michael.zaidman@gmail.com> <20261114230800.1344401-12-michael.zaidman@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 14 Nov 2026 23:27:40 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > FTDI errata TN_189 (Section 2.1) documents a silicon bug where the > FT260's USB interrupt endpoints are occasionally halted right after > enumeration. When this happens, Clear-Feature ENDPOINT_HALT does not > recover the endpoint and the only known recovery is a USB device reset. >=20 > Implement a workaround: >=20 > 1. ft260_check_intr_ep_health() observes the STALL by attempting an > actual interrupt IN transfer. The FT260 does not honestly report > its halt state via USB_REQ_GET_STATUS (returns 0 even when > STALLed; confirmed separately by FTDI engineering [1] with a > USB analyzer trace), so we cannot rely on it; instead we let the > host controller return -EPIPE when it sees the STALL handshake. >=20 > 2. ft260_check_dev_responsive() catches the broader broken state > [ ... ] >=20 > Reported-by: Andreas Boose > Closes: https://github.com/MichaelZaidman/hid-ft260/issues/40 [1] > Link: https://ftdichip.com/wp-content/uploads/2026/05/TN_189-FT260-Errata= -Technical-Note.pdf > Signed-off-by: Michael Zaidman Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261114230800.1344= 401-1-michael.zaidman@gmail.com?part=3D11