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authorPaul Zimmerman <Paul.Zimmerman@synopsys.com>2011-02-12 14:06:44 -0800
committerAK <andi@firstfloor.org>2011-03-31 11:58:14 -0700
commit25d6b22368f95c5ef83f1ee7313d3b66fbf027d3 (patch)
tree3a9d64d8aed2c19afc14d764a6a5c86946269339 /drivers
parentf239e2d130e493b80338290722c902f0e6e3198d (diff)
xhci: Clarify some expressions in the TRB math
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> Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/host/xhci-ring.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 3f2670dca04c..88ea01bec7ec 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1890,7 +1890,7 @@ 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++;
@@ -1920,11 +1920,11 @@ 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,
@@ -2051,8 +2051,7 @@ 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;
@@ -2088,7 +2087,7 @@ 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),
@@ -2132,7 +2131,7 @@ 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 =
@@ -2171,7 +2170,7 @@ 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
@@ -2211,8 +2210,8 @@ 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;