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authorIlpo Järvinen <ilpo.jarvinen@linux.intel.com>2022-09-01 17:39:32 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-09-07 16:40:16 +0200
commite77cab77f2cb3a1ca2ba8df4af45bb35617ac16d (patch)
tree321140bf658608a5eeeea944ef2710a25f8dcaf4 /include
parent7e18e42e4b280c85b76967a9106a13ca61c16179 (diff)
serial: Create uart_xmit_advance()
A very common pattern in the drivers is to advance xmit tail index and do bookkeeping of Tx'ed characters. Create uart_xmit_advance() to handle it. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: stable <stable@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220901143934.8850-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/serial_core.h17
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 6e4f4765d209..1eaea9fe44d8 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -624,6 +624,23 @@ struct uart_state {
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
+/**
+ * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars
+ * @up: uart_port structure describing the port
+ * @chars: number of characters sent
+ *
+ * This function advances the tail of circular xmit buffer by the number of
+ * @chars transmitted and handles accounting of transmitted bytes (into
+ * @up's icount.tx).
+ */
+static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars)
+{
+ struct circ_buf *xmit = &up->state->xmit;
+
+ xmit->tail = (xmit->tail + chars) & (UART_XMIT_SIZE - 1);
+ up->icount.tx += chars;
+}
+
struct module;
struct tty_driver;