Commit eb87ff05 authored by Rene Stange's avatar Rene Stange Committed by Peter Maydell
Browse files

bcm2835_dma: Fix the ylen loop in TD mode 



In TD (two dimensions) DMA mode ylen has to be increased by one after
reading it from the TXFR_LEN register, because a value of zero has to
result in one run through of the ylen loop. This has been tested on a
real Raspberry Pi 3 Model B+. In the previous implementation the ylen
loop was not passed at all for a value of zero.

Signed-off-by: default avatarRene Stange <rsta2@o2online.de>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent d63d0ec5

hw/dma/bcm2835_dma.c

+2 −2
Original line number Diff line number Diff line
@@ -70,14 +70,14 @@ static void bcm2835_dma_update(BCM2835DMAState *s, unsigned c) 
        ch->stride = ldl_le_phys(&s->dma_as, ch->conblk_ad + 16);

        ch->nextconbk = ldl_le_phys(&s->dma_as, ch->conblk_ad + 20);



        ylen = 1;

        if (ch->ti & BCM2708_DMA_TDMODE) {

            /* 2D transfer mode */

            ylen = (ch->txfr_len >> 16) & 0x3fff;

            ylen += (ch->txfr_len >> 16) & 0x3fff;

            xlen = ch->txfr_len & 0xffff;

            dst_stride = ch->stride >> 16;

            src_stride = ch->stride & 0xffff;

        } else {

            ylen = 1;

            xlen = ch->txfr_len;

            dst_stride = 0;

            src_stride = 0;