[3.16.y-ckt stable] Patch "Bluetooth: ath3k: workaround the compatibility issue with xHCI controller" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Bluetooth: ath3k: workaround the compatibility issue with xHCI controller

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From bff6626d83c9ae44b4a5034ffcead3198417291b Mon Sep 17 00:00:00 2001
From: Adam Lee <adam.lee at canonical.com>
Date: Wed, 28 Jan 2015 15:30:27 -0500
Subject: Bluetooth: ath3k: workaround the compatibility issue with xHCI
 controller

commit c561a5753dd631920c4459a067d22679b3d110d6 upstream.

BugLink: https://bugs.launchpad.net/bugs/1400215

ath3k devices fail to load firmwares on xHCI buses, but work well on
EHCI, this might be a compatibility issue between xHCI and ath3k chips.
As my testing result, those chips will work on xHCI buses again with
this patch.

This workaround is from Qualcomm, they also did some workarounds in
Windows driver.

Signed-off-by: Adam Lee <adam.lee at canonical.com>
Signed-off-by: Marcel Holtmann <marcel at holtmann.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/bluetooth/ath3k.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/bluetooth/ath3k.c b/drivers/bluetooth/ath3k.c
index a5075bb1c47f..ccb1adf930e6 100644
--- a/drivers/bluetooth/ath3k.c
+++ b/drivers/bluetooth/ath3k.c
@@ -170,6 +170,8 @@ static const struct usb_device_id ath3k_blist_tbl[] = {
 #define USB_REQ_DFU_DNLOAD	1
 #define BULK_SIZE		4096
 #define FW_HDR_SIZE		20
+#define TIMEGAP_USEC_MIN	50
+#define TIMEGAP_USEC_MAX	100

 static int ath3k_load_firmware(struct usb_device *udev,
 				const struct firmware *firmware)
@@ -201,6 +203,9 @@ static int ath3k_load_firmware(struct usb_device *udev,
 	pipe = usb_sndbulkpipe(udev, 0x02);

 	while (count) {
+		/* workaround the compatibility issue with xHCI controller*/
+		usleep_range(TIMEGAP_USEC_MIN, TIMEGAP_USEC_MAX);
+
 		size = min_t(uint, count, BULK_SIZE);
 		memcpy(send_buf, firmware->data + sent, size);

@@ -296,6 +301,9 @@ static int ath3k_load_fwfile(struct usb_device *udev,
 	count -= size;

 	while (count) {
+		/* workaround the compatibility issue with xHCI controller*/
+		usleep_range(TIMEGAP_USEC_MIN, TIMEGAP_USEC_MAX);
+
 		size = min_t(uint, count, BULK_SIZE);
 		pipe = usb_sndbulkpipe(udev, 0x02);

--
2.1.4