Re: [PATCH 07/10] xhci: Use command structures when queuing commands on the command ring
From: Dan Williams
Date: Thu Jun 05 2014 - 18:16:44 EST
Hi Mathias, hit a small issue playing with -next:
On Thu, May 8, 2014 at 9:26 AM, Mathias Nyman
<mathias.nyman@xxxxxxxxxxxxxxx> wrote:
> To create a global command queue we require that each command put on the
> command ring is submitted with a command structure.
>
> Functions that queue commands and wait for completion need to allocate a command
> before submitting it, and free it once completed. The following command queuing
> functions need to be modified.
>
> xhci_configure_endpoint()
> xhci_address_device()
> xhci_queue_slot_control()
> xhci_queue_stop_endpoint()
> xhci_queue_new_dequeue_state()
> xhci_queue_reset_ep()
> xhci_configure_endpoint()
>
> xhci_configure_endpoint() could already be called with a command structure,
> and only xhci_check_maxpacket and xhci_check_bandwidth did not do so. These
> are changed and a command structure is now required. This change also simplifies
> the configure endpoint command completion handling and the "goto bandwidth_change"
> handling code can be removed.
>
> In some cases the command queuing function is called in interrupt context.
> These commands needs to be allocated atomically, and they can't wait for
> completion. These commands will in this patch be freed directly after queuing,
> but freeing will be moved to the command completion event handler in a later
> patch once we get the global command queue up.(Just so that we won't leak
> memory in the middle of the patch set)
>
> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/host/xhci-hub.c | 21 +++--
> drivers/usb/host/xhci-ring.c | 107 +++++++++++++-----------
> drivers/usb/host/xhci.c | 194 ++++++++++++++++++++++++++++---------------
> drivers/usb/host/xhci.h | 31 +++----
> 4 files changed, 216 insertions(+), 137 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index 1ad6bc1..3ce9c0a 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -20,7 +20,8 @@
> * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> */
>
> -#include <linux/gfp.h>
> +
> +#include <linux/slab.h>
> #include <asm/unaligned.h>
>
> #include "xhci.h"
> @@ -284,12 +285,22 @@ static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
>
> spin_lock_irqsave(&xhci->lock, flags);
> for (i = LAST_EP_INDEX; i > 0; i--) {
> - if (virt_dev->eps[i].ring && virt_dev->eps[i].ring->dequeue)
> - xhci_queue_stop_endpoint(xhci, slot_id, i, suspend);
> + if (virt_dev->eps[i].ring && virt_dev->eps[i].ring->dequeue) {
> + struct xhci_command *command;
> + command = xhci_alloc_command(xhci, false, false,
> + GFP_NOIO);
...this needs to be GFP_NOWAIT, or move it outside the lock.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/