bcm27xx: import latest patches from the RPi foundation

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0748-media-bcm2835-unicam-change-minimum-number-of-vb2_qu.patch b/target/linux/bcm27xx/patches-5.4/950-0748-media-bcm2835-unicam-change-minimum-number-of-vb2_qu.patch
new file mode 100644
index 0000000000..6f14ffc02c
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0748-media-bcm2835-unicam-change-minimum-number-of-vb2_qu.patch
@@ -0,0 +1,28 @@
+From f70be37d1bd6b68ed38022580b16c972598901e2 Mon Sep 17 00:00:00 2001
+From: David Plowman <david.plowman@raspberrypi.com>
+Date: Thu, 28 May 2020 11:09:48 +0100
+Subject: [PATCH] media: bcm2835-unicam: change minimum number of
+ vb2_queue buffers to 1
+
+Since the unicam driver was modified to write to a dummy buffer when no
+user-supplied buffer is available, it can now write to and return a
+buffer even when there's only a single one. Enable this by changing the
+min_buffers_needed in the vb2_queue; it will be useful for enabling
+still captures without allocating more memory than absolutely necessary.
+
+Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
+---
+ drivers/media/platform/bcm2835/bcm2835-unicam.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
++++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
+@@ -2404,7 +2404,7 @@ static int register_node(struct unicam_d
+ 	q->buf_struct_size = sizeof(struct unicam_buffer);
+ 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+ 	q->lock = &node->lock;
+-	q->min_buffers_needed = 2;
++	q->min_buffers_needed = 1;
+ 	q->dev = &unicam->pdev->dev;
+ 
+ 	ret = vb2_queue_init(q);