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Patch "usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet" has been added to the 4.13-stable tree

PATCH [email protected] 1 participant 1 message Oct 15, 2017

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This is a note to let you know that I've just added the patch titled

usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet

to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
usb-renesas_usbhs-fix-dmac-sequence-for-receiving-zero-length-packet.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 29c7f3e68eec4ae94d85ad7b5dfdafdb8089f513 Mon Sep 17 00:00:00 2001

From: Kazuya Mizuguchi <[email protected]>
Date: Mon, 2 Oct 2017 14:01:41 +0900
Subject: usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet

From: Kazuya Mizuguchi <[email protected]>

commit 29c7f3e68eec4ae94d85ad7b5dfdafdb8089f513 upstream.

The DREQE bit of the DnFIFOSEL should be set to 1 after the DE bit of USB-DMAC on R-Car SoCs is set to 1 after the USB-DMAC received a zero-length packet. Otherwise, a transfer completion interruption of USB-DMAC doesn't happen. Even if the driver changes the sequence, normal operations (transmit/receive without zero-length packet) will not cause any side-effects. So, this patch fixes the sequence anyway.

[shimoda: revise the commit log]
Fixes e73a9891b3a1 ("usb: renesas_usbhs: add DMAEngine support")
---
 drivers/usb/renesas_usbhs/fifo.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/usb/renesas_usbhs/fifo.c +1 -1
@@ -857,9 +857,9 @@ static void xfer_work(struct work_struct
 		fifo->name, usbhs_pipe_number(pipe), pkt->length, pkt->zero);
 
 	usbhs_pipe_running(pipe, 1);
-	usbhsf_dma_start(pipe, fifo);
 	usbhs_pipe_set_trans_count_if_bulk(pipe, pkt->trans);
 	dma_async_issue_pending(chan);
+	usbhsf_dma_start(pipe, fifo);
 	usbhs_pipe_enable(pipe);
 
 xfer_work_end:

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/usb-renesas_usbhs-fix-dmac-sequence-for-receiving-zero-length-packet.patch