From: Rasmus Villemoes <ravi@prevas.dk>
Date: Thu, 3 Oct 2024 14:10:29 +0000 (+0200)
Subject: serial: embed the rx buffer in struct serial_dev_priv
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=6cc6a2f6992ebe0c087a0da29d1ded3f8799d6ca;p=u-boot.git

serial: embed the rx buffer in struct serial_dev_priv

The initialization of upriv->buf doesn't check for a NULL return. But
there's actually no point in doing a separate, unconditional malloc()
in post_probe; we can just make serial_dev_priv contain the rx buffer
itself, and let the (larger) allocation be handled by the driver core
when it allocates the ->per_device_auto. The total run-time memory
used is mostly the same, we reduce the code size a little, and as a
bonus, struct serial_dev_priv does not contain the unused members when
!SERIAL_RX_BUFFER.

Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Simon Glass <sjg@chromium.org>
---

diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c
index 484f0f7d3e..d737e25223 100644
--- a/drivers/serial/serial-uclass.c
+++ b/drivers/serial/serial-uclass.c
@@ -588,11 +588,6 @@ static int serial_post_probe(struct udevice *dev)
 	sdev.getc = serial_stub_getc;
 	sdev.tstc = serial_stub_tstc;
 
-#if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
-	/* Allocate the RX buffer */
-	upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
-#endif
-
 	stdio_register_dev(&sdev, &upriv->sdev);
 #endif
 	return 0;
diff --git a/include/serial.h b/include/serial.h
index 14563239b7..eabc49f820 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -298,9 +298,11 @@ struct dm_serial_ops {
 struct serial_dev_priv {
 	struct stdio_dev *sdev;
 
-	char *buf;
+#if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
+	char buf[CONFIG_SERIAL_RX_BUFFER_SIZE];
 	uint rd_ptr;
 	uint wr_ptr;
+#endif
 };
 
 /* Access the serial operations for a device */