This fixes high CPU usage when writing beacon frame to hardware. With this
patch CPU usage of kworker on Intel Atom with 100 TU beacon interval goes
from ~10% down to <1%.
Checking vendor driver appears it's also ignoring fact that endpoints are
interrupt type and is using bulk urbs on these.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@xxxxxxxx>
---
drivers/net/wireless/zd1211rw/zd_usb.c | 62 +++++++++++++++++++++++---------
drivers/net/wireless/zd1211rw/zd_usb.h | 1 -
2 files changed, 44 insertions(+), 19 deletions(-)
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index f6df366..65aff96 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -452,19 +452,6 @@ resubmit:
return;
}
-static inline int int_urb_interval(struct usb_device *udev)
-{
- switch (udev->speed) {
- case USB_SPEED_HIGH:
- return 4;
- case USB_SPEED_LOW:
- return 10;
- case USB_SPEED_FULL:
- default:
- return 1;
- }
-}
-
static inline int usb_int_enabled(struct zd_usb *usb)
{
unsigned long flags;
@@ -511,10 +498,9 @@ int zd_usb_enable_int(struct zd_usb *usb)
goto error_set_urb_null;
}
- usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
+ usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_INT_IN),
intr->buffer, USB_MAX_EP_INT_BUFFER,
- int_urb_complete, usb,
- intr->interval);
+ int_urb_complete, usb);
urb->transfer_dma = intr->buffer_dma;
urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
@@ -1118,7 +1104,6 @@ static inline void init_usb_interrupt(struct zd_usb *usb)
struct zd_usb_interrupt *intr = &usb->intr;
spin_lock_init(&intr->lock);
- intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
init_completion(&intr->read_regs.completion);
intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
}
@@ -1263,10 +1248,32 @@ static int eject_installer(struct usb_interface *intf)
return 0;
}
+static int usb_endpoint_int_to_bulk(struct usb_device *udev, unsigned int pipe)
+{
+ struct usb_host_endpoint *ep;
+
+ ep = usb_pipe_endpoint(udev, pipe);
+ if (!ep)
+ return -EPIPE;
+
+ switch (ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+ case USB_ENDPOINT_XFER_INT:
+ ep->desc.bmAttributes &= ~USB_ENDPOINT_XFERTYPE_MASK;
+ ep->desc.bmAttributes |= USB_ENDPOINT_XFER_BULK;
+ ep->desc.bInterval = 0;
+ /* passthru */
+ case USB_ENDPOINT_XFER_BULK:
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
int zd_usb_init_hw(struct zd_usb *usb)
{
int r;
struct zd_mac *mac = zd_usb_to_mac(usb);
+ struct usb_device *udev = zd_usb_to_usbdev(usb);
dev_dbg_f(zd_usb_dev(usb), "\n");
@@ -1277,13 +1284,32 @@ int zd_usb_init_hw(struct zd_usb *usb)
return r;
}
- r = usb_reset_configuration(zd_usb_to_usbdev(usb));
+ r = usb_reset_configuration(udev);
if (r) {
dev_dbg_f(zd_usb_dev(usb),
"couldn't reset configuration. Error number %d\n", r);
return r;
}
+ /* Change EP_REGS_OUT and EP_INT_IN to bulk endpoints. This solves high
+ * CPU usage of zd_mac_beacon_config.
+ */
+ r = usb_endpoint_int_to_bulk(udev, usb_sndintpipe(udev, EP_REGS_OUT));
+ if (r) {
+ dev_dbg_f(zd_usb_dev(usb),
+ "couldn't change EP_REGS_OUT endpoint type to bulk. "
+ "Error number %d\n", r);
+ return r;
+ }
+
+ r = usb_endpoint_int_to_bulk(udev, usb_rcvintpipe(udev, EP_INT_IN));
+ if (r) {
+ dev_dbg_f(zd_usb_dev(usb),
+ "couldn't change EP_INT_IN endpoint type to bulk. "
+ "Error number %d\n", r);
+ return r;
+ }
+
r = zd_mac_init_hw(mac->hw);
if (r) {
dev_dbg_f(zd_usb_dev(usb),
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.h b/drivers/net/wireless/zd1211rw/zd_usb.h
index 2d688f4..333bb84 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.h
+++ b/drivers/net/wireless/zd1211rw/zd_usb.h
@@ -168,7 +168,6 @@ struct zd_usb_interrupt {
struct urb *urb;
void *buffer;
dma_addr_t buffer_dma;
- int interval;
u8 read_regs_enabled:1;
};
--
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