haraldwolff/qemu-patch-raspberry4
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bcm2835_dma: Fix the ylen loop in TD mode

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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: Rene Stange <rsta2@o2online.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Rene Stange 2020-02-07 14:04:27 +00:00 committed by Peter Maydell
parent d63d0ec59d
commit eb87ff05ea
1 changed files with 2 additions and 2 deletions
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4
hw/dma/bcm2835_dma.c
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@ -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;