From 896720ceb2cededcd1f25fa5f5ff23822bea466d Mon Sep 17 00:00:00 2001 From: Nikhil Badola Date: Mon, 7 Apr 2014 08:46:14 +0530 Subject: fsl/usb: Increase TXFIFOTHRESH value for usb write in T4 Rev 2.0 Increase TXFIFOTHRES field value in TXFILLTUNING register of usb for T4 Rev 2.0. This decreases data burst rate with which data packets are posted from the TX latency FIFO to compensate for latencies in DDR pipeline during DMA. This avoids Tx buffer underruns and leads to successful usb writes Signed-off-by: Ramneek Mehresh Signed-off-by: Nikhil Badola Reviewed-by: York Sun --- include/usb/ehci-fsl.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/usb/ehci-fsl.h') diff --git a/include/usb/ehci-fsl.h b/include/usb/ehci-fsl.h index 734305b..c9ee1d5 100644 --- a/include/usb/ehci-fsl.h +++ b/include/usb/ehci-fsl.h @@ -164,6 +164,13 @@ #endif /* + * Increasing TX FIFO threshold value from 2 to 4 decreases + * data burst rate with which data packets are posted from the TX + * latency FIFO to compensate for latencies in DDR pipeline during DMA + */ +#define TXFIFOTHRESH 4 + +/* * USB Registers */ struct usb_ehci { -- cgit v1.1