From c5603e2a621dac10c5e21cc430848ebcfa6c7e01 Mon Sep 17 00:00:00 2001 From: Doug Brown Date: Thu, 6 Jun 2024 12:56:31 -0700 Subject: Revert "serial: core: only stop transmit when HW fifo is empty" This reverts commit 7bfb915a597a301abb892f620fe5c283a9fdbd77. This commit broke pxa and omap-serial, because it inhibited them from calling stop_tx() if their TX FIFOs weren't completely empty. This resulted in these two drivers hanging during transmits because the TX interrupt would stay enabled, and a new TX interrupt would never fire. Cc: stable@vger.kernel.org Fixes: 7bfb915a597a ("serial: core: only stop transmit when HW fifo is empty") Signed-off-by: Doug Brown Link: https://lore.kernel.org/r/20240606195632.173255-2-doug@schmorgal.com Signed-off-by: Greg Kroah-Hartman --- include/linux/serial_core.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include/linux/serial_core.h') diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 8cb65f50e830..3fb9a29e025f 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -811,8 +811,7 @@ enum UART_TX_FLAGS { if (pending < WAKEUP_CHARS) { \ uart_write_wakeup(__port); \ \ - if (!((flags) & UART_TX_NOSTOP) && pending == 0 && \ - __port->ops->tx_empty(__port)) \ + if (!((flags) & UART_TX_NOSTOP) && pending == 0) \ __port->ops->stop_tx(__port); \ } \ \ -- cgit v1.2.3 From 9bb43b9e8d9a288a214e9b17acc9e46fda3977cf Mon Sep 17 00:00:00 2001 From: Jonas Gorski Date: Thu, 6 Jun 2024 12:56:32 -0700 Subject: serial: core: introduce uart_port_tx_limited_flags() Analogue to uart_port_tx_flags() introduced in commit 3ee07964d407 ("serial: core: introduce uart_port_tx_flags()"), add a _flags variant for uart_port_tx_limited(). Fixes: d11cc8c3c4b6 ("tty: serial: use uart_port_tx_limited()") Cc: stable@vger.kernel.org Signed-off-by: Jonas Gorski Signed-off-by: Doug Brown Link: https://lore.kernel.org/r/20240606195632.173255-3-doug@schmorgal.com Signed-off-by: Greg Kroah-Hartman --- include/linux/serial_core.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/serial_core.h') diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 3fb9a29e025f..aea25eef9a1a 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -850,6 +850,24 @@ enum UART_TX_FLAGS { __count--); \ }) +/** + * uart_port_tx_limited_flags -- transmit helper for uart_port with count limiting with flags + * @port: uart port + * @ch: variable to store a character to be written to the HW + * @flags: %UART_TX_NOSTOP or similar + * @count: a limit of characters to send + * @tx_ready: can HW accept more data function + * @put_char: function to write a character + * @tx_done: function to call after the loop is done + * + * See uart_port_tx_limited() for more details. + */ +#define uart_port_tx_limited_flags(port, ch, flags, count, tx_ready, put_char, tx_done) ({ \ + unsigned int __count = (count); \ + __uart_port_tx(port, ch, flags, tx_ready, put_char, tx_done, __count, \ + __count--); \ +}) + /** * uart_port_tx -- transmit helper for uart_port * @port: uart port -- cgit v1.2.3