aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.19/950-0814-overlays-dwc2-Increase-RX-FIFO-size.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0814-overlays-dwc2-Increase-RX-FIFO-size.patch')
-rw-r--r--target/linux/brcm2708/patches-4.19/950-0814-overlays-dwc2-Increase-RX-FIFO-size.patch32
1 files changed, 32 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0814-overlays-dwc2-Increase-RX-FIFO-size.patch b/target/linux/brcm2708/patches-4.19/950-0814-overlays-dwc2-Increase-RX-FIFO-size.patch
new file mode 100644
index 0000000000..a8e7bd3c90
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0814-overlays-dwc2-Increase-RX-FIFO-size.patch
@@ -0,0 +1,32 @@
+From 389107911744588cce5e06c23a058c9cfb641f33 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.com>
+Date: Tue, 4 Feb 2020 13:03:21 +0000
+Subject: [PATCH] overlays: dwc2: Increase RX FIFO size
+
+The previous version of the dwc2 overlay set the RX FIFO size to
+256 4-byte words. This sounds large enough for a 1024 byte packet (the
+largest isochronous high speed packet allowed), but it doesn't take
+into account some extra space needed by the hardware.
+
+Minas Harutyunyan at Synopsys (the source of the DWC OTG design)
+came up with a more correct value, 301, but since there is spare packet
+RAM this can be increased to 558 to allow two packets per frame.
+
+See: https://github.com/raspberrypi/linux/issues/3447
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.com>
+---
+ arch/arm/boot/dts/overlays/dwc2-overlay.dts | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/arm/boot/dts/overlays/dwc2-overlay.dts
++++ b/arch/arm/boot/dts/overlays/dwc2-overlay.dts
+@@ -12,7 +12,7 @@
+ compatible = "brcm,bcm2835-usb";
+ dr_mode = "otg";
+ g-np-tx-fifo-size = <32>;
+- g-rx-fifo-size = <256>;
++ g-rx-fifo-size = <558>;
+ g-tx-fifo-size = <512 512 512 512 512 256 256>;
+ status = "okay";
+ };