This patch (as1296) gets rid of the fixed DMA-buffer mapping used by
the hub driver for its status URB. This URB doesn't get used much --
mainly when a device is plugged in or unplugged -- so the dynamic
mapping overhead is minimal. And most systems have many fewer
external hubs than root hubs, which don't need a mapped buffer anyway.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
Index: usb-2.6/drivers/usb/core/hub.c
===================================================================
--- usb-2.6.orig/drivers/usb/core/hub.c
+++ usb-2.6/drivers/usb/core/hub.c
@@ -45,7 +45,6 @@ struct usb_hub {
/* buffer for urb ... with extra space in case of babble */
char (*buffer)[8];
- dma_addr_t buffer_dma; /* DMA address for buffer */
union {
struct usb_hub_status hub;
struct usb_port_status port;
@@ -905,8 +904,7 @@ static int hub_configure(struct usb_hub
int maxp, ret;
char *message = "out of memory";
- hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
- &hub->buffer_dma);
+ hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
if (!hub->buffer) {
ret = -ENOMEM;
goto fail;
@@ -1147,8 +1145,6 @@ static int hub_configure(struct usb_hub
usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
hub, endpoint->bInterval);
- hub->urb->transfer_dma = hub->buffer_dma;
- hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
/* maybe cycle the hub leds */
if (hub->has_indicators && blinkenlights)
@@ -1198,8 +1194,7 @@ static void hub_disconnect(struct usb_in
kfree(hub->port_owners);
kfree(hub->descriptor);
kfree(hub->status);
- usb_buffer_free(hub->hdev, sizeof(*hub->buffer), hub->buffer,
- hub->buffer_dma);
+ kfree(hub->buffer);
kref_put(&hub->kref, hub_release);
}
--
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