From patchwork Mon Mar 17 07:00:26 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 874687 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E012A21ABB7; Mon, 17 Mar 2025 07:01:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742194868; cv=none; b=BGA+WsHl/OrWQqdhQ0nnJ4nVs1obbDV7BzpG8BWJLJdt56Mv5SIx7cYc1f4kQkEzvHsgxiKJPtRnvfJe4nLALh2qIjjT5btFxkL5D84qI8s2bizhjbopcYozhNrW6qH7yg3ssqYCVV/JgFWFJKBPpnyoh0uMZgFKl08yP9OVII4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742194868; c=relaxed/simple; bh=OCRjQPfORu1jFCTk4sWvvQt3O/fs8afQ659O4ETP8QA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Dih6Q8LNRvZ5reaIUCETwpWUMGv8GiAyTCivPWEGfm1k+2mHwShEmIUZxckRF0SmgcHYksSkzm5GxsRA7PAX9jear3Q9Di5wNDrJH1DyY6ecvN7JrCaWzUqBazOBc4fsjx2fDpVJCmiP9OD3yLoMLmqlGjcw+J30N2QfWyOUrnE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ujYvSyjZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ujYvSyjZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47A9CC4CEEC; Mon, 17 Mar 2025 07:01:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742194867; bh=OCRjQPfORu1jFCTk4sWvvQt3O/fs8afQ659O4ETP8QA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ujYvSyjZc4z8Ud75Rc6FZCsmekXHF3sAb72Xl0Aqd4dOW34HJ5pw75SBUPTXV7wIP y4z1tQlL30xtJXKbewqezaLzbPNYX42PMs1Do4s0U+jMKaMH0FSZ6A0NzjyXYHc6jk A211+0shszF3KRWolV9KATAJOix8vdrPpIadXmMa0de6w9JxjXLpK+Knx4kkKwI/51 RQy6x2iCl/HEXvoS9BBT+UV82dbWc5xDdySonpQKcyDRplGu99BOqihpAhukp1XRfY UXbINEoem27TCxDfnHYa08umDKowmDtucE/heghNcDdolbjV2gA4JhmFHDQQ4ecD1U l6I2KGklfY7tw== From: "Jiri Slaby (SUSE)" To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Jiri Slaby (SUSE)" Subject: [PATCH v2 11/31] tty: n_tty: move more_to_be_read to the end of n_tty_read() Date: Mon, 17 Mar 2025 08:00:26 +0100 Message-ID: <20250317070046.24386-12-jirislaby@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250317070046.24386-1-jirislaby@kernel.org> References: <20250317070046.24386-1-jirislaby@kernel.org> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 n_tty_read() contains "we need more data" handling deep in that function. And there is also a label (more_to_be_read) as we handle this situation from two places. It makes more sense to have all "return"s accumulated at the end of functions. And "goto" from multiple places there. Therefore, do this with the "more_to_be_read" label in n_tty_read(). After this and the previous changes, n_tty_read() is now much more easier to follow. Signed-off-by: Jiri Slaby (SUSE) --- drivers/tty/n_tty.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 0e3eb18490f0..6af3f3a0b531 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -2281,21 +2281,8 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf, nr--; } - /* - * Copy data, and if there is more to be had - * and we have nothing more to wait for, then - * let's mark us for retries. - * - * NOTE! We return here with both the termios_sem - * and atomic_read_lock still held, the retries - * will release them when done. - */ - if (copy_from_read_buf(tty, &kb, &nr) && kb - kbuf >= minimum) { -more_to_be_read: - remove_wait_queue(&tty->read_wait, &wait); - *cookie = cookie; - return kb - kbuf; - } + if (copy_from_read_buf(tty, &kb, &nr) && kb - kbuf >= minimum) + goto more_to_be_read; } n_tty_check_unthrottle(tty); @@ -2322,6 +2309,18 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf, retval = kb - kbuf; return retval; +more_to_be_read: + /* + * There is more to be had and we have nothing more to wait for, so + * let's mark us for retries. + * + * NOTE! We return here with both the termios_sem and atomic_read_lock + * still held, the retries will release them when done. + */ + remove_wait_queue(&tty->read_wait, &wait); + *cookie = cookie; + + return kb - kbuf; } /**