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=1792588760; b=mcyBxj1Cb++Gb8yX2vL+6NpTc7/+fTtGXMB8QK3mdF985ETRTgbWdoGuiLijmmiVkaRX NZTvo2Vci4T2nw2p9KeByjo5f5aF5/WAruUKbzqN+LMeVOT++XricdYil1BgNhq2F/0tb PqUev5kn62QA3Sgk/Jen+ZWpsuDiNp2zBCOrbkNqb72r0lMOLEfZnVGL2xcSSYgVpeUg4 u6hhOtxZ88hs7anqk2KjS6Rl+UeegL1hxLa/m2N44vu42eMmQXCKk385qJsXHp0gP7EQ5 J1DTFP8ys6AxO1ic29MTmHvMF36UcaNp87HC14WvyvYmhf+FknHVCWeP0rlsHOkE3fA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792588760; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=wX+ypAi0Bd7InDAjZ8AwCPFwT9uOr5hA5C2EE6mjTJs=; b=sR+qF5VlaKRkO6kIzzIuVOLgS/jMHrgZiQCYixPcjyMt8BF2b7JzHRMH428s/Tdj0gr7 qnNQM9YRls8owYGpLIyimwGCEXjDyLF1vkXKuhUASIrCLTHZ4WCJqKoRJLNCZlABSnhqa Crgl9+yd9ZSOw5oFzMWnGyNIe3JDe6Tq502zAY9S7YUFuXXIvXOUT62b66z4UrrZ5hUNB Uu1YsP9SYQntWyjL13ZbTqexL9qPHSj8+eXCgEDJZpKXQ22zgfx6VL/g94mUrVtoJxQ/N w6n+bDJppzIV30FDZR1QVXBain4X/mstirH4pcW6w9Nvw008MqDn49GzCWRYOPyyTbQ== 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=Dw+bkzz8; 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 BBB29606A319 for ; Wed, 21 Oct 2026 13:19:19 +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=Dw+bkzz8 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46A0B1F000C5; Wed, 21 Oct 2026 13:19:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792588759; bh=wX+ypAi0Bd7InDAjZ8AwCPFwT9uOr5hA5C2EE6mjTJs=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Dw+bkzz8iVaynFzstK6fgJ6DMfiL5vp+NOYaiFjAixh+cM5OtvFnLixrg1R15OTt8 9dD5oVZKuGDP5ZDcPArc30JhAhdIp029LrbK+IWFidZpydbzgrxuPRGiMjBZC7O20o Va/JIsXapv0Wh0GkNR0/B/LgLE6JxHelwJNkVWbqxt29mBuCL0vv71BQcQrB1fLVRf +qjUsOhzBJby409Su2q76EP0zN+1arz2bKDFWc3p87EfKjFHCc26mUTzuaoaSerwv/ XwXmkAQCDD7jq7DbhxqresGvr6UYbPH1NyO8mVckcwy8OfEH4V92c30k2MV/lH+mXZ sEZZoekkjkvxQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 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: <20261021-g2ul_sci-v2-4-b4e038220018@bp.renesas.com> References: <20261021-g2ul_sci-v2-0-b4e038220018@bp.renesas.com> <20261021-g2ul_sci-v2-4-b4e038220018@bp.renesas.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 21 Oct 2026 13:19:18 +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/20261021-g2ul_sci-v= 2-0-b4e038220018@bp.renesas.com?part=3D4