Commit b9d2dde0 authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman

Staging: et131x: Correct WRAP bit handling

add_10bit loses the existing wrap value
Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4439c935
......@@ -1177,12 +1177,20 @@ void et131x_handle_recv_interrupt(struct et131x_adapter *etdev)
static inline u32 bump_fbr(u32 *fbr, u32 limit)
{
u32 v = *fbr;
add_10bit(&v, 1);
if (v > limit)
v = (*fbr & ~ET_DMA10_MASK) ^ ET_DMA10_WRAP;
*fbr = v;
return v;
u32 v = *fbr;
v++;
/* This works for all cases where limit < 1024. The 1023 case
works because 1023++ is 1024 which means the if condition is not
taken but the carry of the bit into the wrap bit toggles the wrap
value correctly */
if ((v & ET_DMA10_MASK) > limit) {
v &= ~ET_DMA10_MASK;
v ^= ET_DMA10_WRAP;
}
/* For the 1023 case */
v &= (ET_DMA10_MASK|ET_DMA10_WRAP);
*fbr = v;
return v;
}
/**
......
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