[PATCH 3.19 002/175] Bluetooth: ath3k: workaround the compatibility issue with xHCI controller

Greg Kroah-Hartman
2015-03-04T07:10:15Z

From: Adam Lee <adam.lee@canonical.com>

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@canonical.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/bluetooth/ath3k.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/bluetooth/ath3k.c
+++ b/drivers/bluetooth/ath3k.c
@@ -174,6 +174,8 @@ static const struct usb_device_id ath3k_
#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)
@@ -205,6 +207,9 @@ static int ath3k_load_firmware(struct us
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);

@@ -302,6 +307,9 @@ static int ath3k_load_fwfile(struct usb_
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);