Hi Paul,
On Fri, Jan 14, 2011 at 05:20:03PM -0800, Paul Zimmerman wrote:
> xhci: Clarify some expressions in the TRB math. This makes it easier to spot
^^^^ Did you mean to have "xhci" here?
> some problems which will be fixed by the next patch in the series. Also change
> dev_dbg to dev_err in check_trb_math(), so any math errors will be visible even
> when running with debug disabled.
Can you please add a note that
(TRB_MAX_BUFF_SIZE - 1))
is equivalent to
((1 << TRB_MAX_BUFF_SHIFT) - 1))
since xhci.h includes these three lines:
/* TRB buffer pointers can't cross 64KB boundaries */
#define TRB_MAX_BUFF_SHIFT 16
#define TRB_MAX_BUFF_SIZE (1 << TRB_MAX_BUFF_SHIFT)
I think that will make it clear to the casual observer that this patch
doesn't change any behavior.
Sarah Sharp
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
>
> Signed-off-by: Paul Zimmerman <paulz@xxxxxxxxxxxx>
> ---
> drivers/usb/host/xhci-ring.c | 22 ++++++++++------------
> 1 files changed, 10 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
> index b4be841..fe6dd81 100644
> --- a/drivers/usb/host/xhci-ring.c
> +++ b/drivers/usb/host/xhci-ring.c
> @@ -2374,7 +2374,7 @@ static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
>
> /* Scatter gather list entries may cross 64KB boundaries */
> running_total = TRB_MAX_BUFF_SIZE -
> - (sg_dma_address(sg) & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
> + (sg_dma_address(sg) & (TRB_MAX_BUFF_SIZE - 1));
> if (running_total != 0)
> num_trbs++;
>
> @@ -2404,11 +2404,11 @@ static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
> static void check_trb_math(struct urb *urb, int num_trbs, int running_total)
> {
> if (num_trbs != 0)
> - dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
> + dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
> "TRBs, %d left\n", __func__,
> urb->ep->desc.bEndpointAddress, num_trbs);
> if (running_total != urb->transfer_buffer_length)
> - dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
> + dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
> "queued %#x (%d), asked for %#x (%d)\n",
> __func__,
> urb->ep->desc.bEndpointAddress,
> @@ -2540,8 +2540,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
> sg = urb->sg;
> addr = (u64) sg_dma_address(sg);
> this_sg_len = sg_dma_len(sg);
> - trb_buff_len = TRB_MAX_BUFF_SIZE -
> - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
> + trb_buff_len = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1));
> trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
> if (trb_buff_len > urb->transfer_buffer_length)
> trb_buff_len = urb->transfer_buffer_length;
> @@ -2577,7 +2576,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
> (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
> (unsigned int) addr + trb_buff_len);
> if (TRB_MAX_BUFF_SIZE -
> - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)) < trb_buff_len) {
> + (addr & (TRB_MAX_BUFF_SIZE - 1)) < trb_buff_len) {
> xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n");
> xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n",
> (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
> @@ -2621,7 +2620,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
> }
>
> trb_buff_len = TRB_MAX_BUFF_SIZE -
> - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
> + (addr & (TRB_MAX_BUFF_SIZE - 1));
> trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
> if (running_total + trb_buff_len > urb->transfer_buffer_length)
> trb_buff_len =
> @@ -2661,7 +2660,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
> num_trbs = 0;
> /* How much data is (potentially) left before the 64KB boundary? */
> running_total = TRB_MAX_BUFF_SIZE -
> - (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
> + (urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1));
>
> /* If there's some data on this 64KB chunk, or we have to send a
> * zero-length transfer, we need at least one TRB
> @@ -2704,8 +2703,8 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
> /* How much data is in the first TRB? */
> addr = (u64) urb->transfer_dma;
> trb_buff_len = TRB_MAX_BUFF_SIZE -
> - (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
> - if (urb->transfer_buffer_length < trb_buff_len)
> + (urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1));
> + if (trb_buff_len > urb->transfer_buffer_length)
> trb_buff_len = urb->transfer_buffer_length;
>
> first_trb = true;
> @@ -2877,8 +2876,7 @@ static int count_isoc_trbs_needed(struct xhci_hcd *xhci,
> addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset);
> td_len = urb->iso_frame_desc[i].length;
>
> - running_total = TRB_MAX_BUFF_SIZE -
> - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
> + running_total = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1));
> if (running_total != 0)
> num_trbs++;
>
> --
> 1.6.5.1.69.g36942
>
>
>
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