Messages in this thread Patch in this message | | | Date | Mon, 28 Feb 2011 08:23:27 -0800 | From | Greg KH <> | Subject | [66/68] xhci: Clarify some expressions in the TRB math |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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From: Paul Zimmerman <Paul.Zimmerman@synopsys.com>
commit a2490187011cc2263117626615a581927d19f1d3 upstream.
This makes it easier to spot 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.
Note: This patch changes the expressions containing "((1 << TRB_MAX_BUFF_SHIFT) - 1)" to use the equivalent "(TRB_MAX_BUFF_SIZE - 1)". No change in behavior is intended for those expressions.
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/usb/host/xhci-ring.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)
--- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1490,7 +1490,7 @@ static unsigned int count_sg_trbs_needed /* 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++; @@ -1520,11 +1520,11 @@ static unsigned int count_sg_trbs_needed 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, @@ -1631,8 +1631,7 @@ static int queue_bulk_sg_tx(struct xhci_ sg = urb->sg->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; @@ -1667,7 +1666,7 @@ static int queue_bulk_sg_tx(struct xhci_ (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), @@ -1705,7 +1704,7 @@ static int queue_bulk_sg_tx(struct xhci_ } 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 = @@ -1740,7 +1739,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd * 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 @@ -1779,8 +1778,8 @@ int xhci_queue_bulk_tx(struct xhci_hcd * /* 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;
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