Re: [PATCH v2 2/2] serial: 8250: Use BIT(x) for UART_{CAP,BUG}_*

From: Jiri Slaby
Date: Wed May 19 2021 - 02:14:28 EST


On 19. 05. 21, 2:07, Andrew Jeffery wrote:
BIT(x) improves readability and safety with respect to shifts.

Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx>
---
drivers/tty/serial/8250/8250.h | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 34aa2714f3c9..4fbf1088fad8 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -7,6 +7,7 @@
* Copyright (C) 2001 Russell King.
*/
+#include <linux/bitops.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/dmaengine.h>
@@ -70,25 +71,25 @@ struct serial8250_config {
unsigned int flags;
};
-#define UART_CAP_FIFO (1 << 8) /* UART has FIFO */
-#define UART_CAP_EFR (1 << 9) /* UART has EFR */
-#define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
-#define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
-#define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
-#define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
-#define UART_CAP_HFIFO (1 << 14) /* UART has a "hidden" FIFO */
-#define UART_CAP_RPM (1 << 15) /* Runtime PM is active while idle */
-#define UART_CAP_IRDA (1 << 16) /* UART supports IrDA line discipline */
-#define UART_CAP_MINI (1 << 17) /* Mini UART on BCM283X family lacks:
+#define UART_CAP_FIFO BIT(8) /* UART has FIFO */
+#define UART_CAP_EFR BIT(9) /* UART has EFR */
+#define UART_CAP_SLEEP BIT(10) /* UART has IER sleep */


Perfect, except the include: BIT is not defined in bitops.h, but in bits.h (which includes vdso/bits.h). In fact, bitops.h includes bits.h too, but it's superfluous to include all those bitops.

thanks,
--
--
js
suse labs