From b9d2dde0556cde38105033cb39841658d81921d2 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 12 Oct 2009 15:38:17 +0100 Subject: [PATCH] Staging: et131x: Correct WRAP bit handling add_10bit loses the existing wrap value Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/staging/et131x/et1310_rx.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/staging/et131x/et1310_rx.c b/drivers/staging/et131x/et1310_rx.c index 8f2e91fa0a86..10e21db57ac3 100644 --- a/drivers/staging/et131x/et1310_rx.c +++ b/drivers/staging/et131x/et1310_rx.c @@ -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; } /** -- 2.20.1