From mboxrd@z Thu Jan 1 00:00:00 1970 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 002F3612D7; Tue, 20 Feb 2024 21:18:13 +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=1708463894; cv=none; b=jQTb4Sa5Ix2f8ejyJ3CFbg2WsDUZrF3+VX2BgiedHSucXk1xK+jyBxRa5TjIZt3OaS6WrEtkMg+6KHtC2uHnLjFdECrxCovMOT0432+CdGffg98TSTJL6cEJ/y17XyXHaa3fJ+KYphdB10+YUci6+xM6r0r5DC+8CWz1zA6cdiE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708463894; c=relaxed/simple; bh=kn9Ib6DQWRVDgrPWbqecCJjCTi3FD8USrlr2BpakodU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=abgzDEQuOHTiItHjdPKlqhI8PGVjTPFbpsq94wiqxPvAgpE0Jx/daD5ecuNAgp3vYCu1h7lyM8dzRs9Hd5qnmKlP+SZKSjx1Jp68lK5h/8iRqQHwL9AlL6F04AyX2ov7FnjhJJPmC2mJxjsQkXb5MzaHdwAEOd463Eumy97nOXo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CuTyxBgR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CuTyxBgR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6487BC433C7; Tue, 20 Feb 2024 21:18:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708463893; bh=kn9Ib6DQWRVDgrPWbqecCJjCTi3FD8USrlr2BpakodU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CuTyxBgRPaRS3lplRIHm5PqkowcRYxqTdCeV7irL+Usr8M2t+clHnwntBzXIptj18 2dWJ7y1mmoRGnM3aNIfUxK+9aQidxHlofvY3+YEi6Yzn4UCCD+06djJR2UGiooxFfJ E5BswYrT0csiVVZgySS2Af0BpEvx5GILhx9mFw1M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Jiri Slaby (SUSE)" , stable , Emil Kronborg Subject: [PATCH 6.6 187/331] serial: core: introduce uart_port_tx_flags() Date: Tue, 20 Feb 2024 21:55:03 +0100 Message-ID: <20240220205643.432506096@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240220205637.572693592@linuxfoundation.org> References: <20240220205637.572693592@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Slaby (SUSE) commit 3ee07964d407411fd578a3bc998de44fd64d266a upstream. And an enum with a flag: UART_TX_NOSTOP. To NOT call __port->ops->stop_tx() when the circular buffer is empty. mxs-uart needs this (see the next patch). Signed-off-by: "Jiri Slaby (SUSE)" Cc: stable Tested-by: Emil Kronborg Link: https://lore.kernel.org/r/20240201105557.28043-1-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman --- include/linux/serial_core.h | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -748,8 +748,17 @@ struct uart_driver { void uart_write_wakeup(struct uart_port *port); -#define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test, \ - for_post) \ +/** + * enum UART_TX_FLAGS -- flags for uart_port_tx_flags() + * + * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer + */ +enum UART_TX_FLAGS { + UART_TX_NOSTOP = BIT(0), +}; + +#define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done, \ + for_test, for_post) \ ({ \ struct uart_port *__port = (uport); \ struct circ_buf *xmit = &__port->state->xmit; \ @@ -777,7 +786,7 @@ void uart_write_wakeup(struct uart_port if (pending < WAKEUP_CHARS) { \ uart_write_wakeup(__port); \ \ - if (pending == 0) \ + if (!((flags) & UART_TX_NOSTOP) && pending == 0) \ __port->ops->stop_tx(__port); \ } \ \ @@ -812,7 +821,7 @@ void uart_write_wakeup(struct uart_port */ #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \ unsigned int __count = (count); \ - __uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count, \ + __uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count, \ __count--); \ }) @@ -826,8 +835,21 @@ void uart_write_wakeup(struct uart_port * See uart_port_tx_limited() for more details. */ #define uart_port_tx(port, ch, tx_ready, put_char) \ - __uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({})) + __uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({})) + +/** + * uart_port_tx_flags -- transmit helper for uart_port with flags + * @port: uart port + * @ch: variable to store a character to be written to the HW + * @flags: %UART_TX_NOSTOP or similar + * @tx_ready: can HW accept more data function + * @put_char: function to write a character + * + * See uart_port_tx_limited() for more details. + */ +#define uart_port_tx_flags(port, ch, flags, tx_ready, put_char) \ + __uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({})) /* * Baud rate helpers. */