Commit d697cdda authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: don't use a fixed DMA mapping for hub status URBs 



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: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent dccd574c

drivers/usb/core/hub.c

+2 −7
Original line number Diff line number Diff line
@@ -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;
@@ -869,8 +868,7 @@ static int hub_configure(struct usb_hub *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;
@@ -1111,8 +1109,6 @@ static int hub_configure(struct usb_hub *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)
@@ -1162,8 +1158,7 @@ static void hub_disconnect(struct usb_interface *intf) 
	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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