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=1793015660; b=1vb47rJsxczvIPsZMe0z7VDr2l2lvdQJqG4idCaYNIhXgXrvEYsPKTUP3jr6+MLX7dO3 kr7YOgOlgRQlB8eu047dAV7uPBweSSJzgTK/fUsA3EKzQFfcq2f6NUJDZf0B2rou6PlNU AH/S4TYu7tPtVZjZ8iX5JqGSZdce2EZcemsU4fE1HcQc5DSkPFaimFjDdnn0vW3SquLRm jxeyFWUl2afBSLHzkA9uH1+8+e8gic9X+SfWenJx51bnhc+8A97pFQqqpVgZtq8/Dk3gb 1tewXKDpgIDG/UB0Mvb+E2W1mPCQVmj2Ldm0hcsTLgEaCsCPC+Kwma5VDL/szp8A7hw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793015660; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=szBQZEcEpddLBN5BwYG2iNtTW8g8XkhGaYliBN31E1g=; b=TKnS0kc3YGafrtNgnWyL/h/H59A5dzic6mJn8s1vvf3/7jHVkK6jxVp7qrZxJugQPIfl hfKdKXcVXMzdibyofRSil1viXO6LyV+JFY0dIolNIGYLx5CqjK1YIviI95BpoHIpkbR2l 83NyD479kJ4FL5Js7QXtz6jE2bhmi0dj92zet//6+LY7uN7dpu321NgGEQeEPu7Uzisbt o4R/K6haoM3El663ijIm4HMDwKWmDlegjC97Htu13AHsctUKvpVEOGxX2EY7uBc58leeO zU9xil5uPIuR2rtf6cfDeCzRHQE13+LQPXaZaXCCKtxvFhMgs9vuVjr4zHP1AeOcY+Q== 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="L0F3x/Cz"; 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 B26A1606A31A for ; Mon, 26 Oct 2026 11:54:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=L0F3x/Cz Received: by smtp.kernel.org (Postfix) with ESMTPSA id 459BC1F01825; Mon, 26 Oct 2026 11:54:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793015659; bh=szBQZEcEpddLBN5BwYG2iNtTW8g8XkhGaYliBN31E1g=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=L0F3x/Czb2emR+0PQcuON7CJhh0ZOApHDC0XHfKoznlk+1F1pqcTMUL5dT0uZ/4hI mrSf4UKbDr9B/NytLrICFzDXjdpEW5JUUuorypTXqUQ3TwYFUqdVyj+79z+WIDCwG/ ANNjIOcHtS7hTw447rukqp27vxBhlyG8cpx8cmZRKc7gjvDnDzEwOwKiXT55fhVtL0 jKcx3/T6JFZ30hNG2E29nLfr0NZ7+Ir4rpIG3Knotdcvqw082V0Y6kTPz5UVjCplid DQxFjm97qeYjngeexcLN+08i/+Vh2PYhBzIcTQWQ6VAZTuIRwAxwOi/x3DzWDKInZb 1UjM53VCkNjdg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 4/4] serial: sh-sci: Toggle TE when restoring SCSCR in console write on SCI Reply-To: sashiko-reviews@lists.linux.dev To: "Biju Das" Cc: linux-serial@vger.kernel.org In-Reply-To: <20261026-g2ul_sci-v3-4-b3097163edd5@bp.renesas.com> References: <20261026-g2ul_sci-v3-0-b3097163edd5@bp.renesas.com> <20261026-g2ul_sci-v3-4-b3097163edd5@bp.renesas.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 26 Oct 2026 11:54:18 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Au Dang >=20 > When SCI0 (PORT_SCI) is the system console on RZ/G2UL, the board can > hang at the serial console output stage during boot. >=20 > ftrace shows the following sequence: >=20 > 1. sci_transmit_chars() is draining the TX kfifo through TXI > interrupts with SCSCR=3D0xf0 (TE=3D1, TIE=3D1, RE=3D1, RIE=3D1). >=20 > 2. serial_console_write() runs in the middle of that drain. It saves > SCSCR=3D0xf0, switches to polling by writing SCSCR=3D0x30 (TE=3D1, TIE= =3D0) > and outputs the characters with sci_poll_put_char(). >=20 > 3. It then restores SCSCR=3D0xf0 in a single write. TE is 1 both before > [ ... ] > TIE is being re-enabled, so TXI fires and the interrupted drain > resumes. >=20 > Signed-off-by: Au Dang > Signed-off-by: Biju Das Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261026-g2ul_sci-v= 3-0-b3097163edd5@bp.renesas.com?part=3D4