On Sun, Sep 12, 2021 at 11:11 PM <[email protected]> wrote:
>
> From: Frank Chang <[email protected]>
>
> Real PDMA doesn't set Control.error if there are 0 bytes to be
> transferred. The DMA transfer is still success.
>
> The following result is PDMA tested in U-Boot on Unmatched board:
>
> => mw.l 0x3000000 0x0 <= Disclaim channel 0
> => mw.l 0x3000000 0x1 <= Claim channel 0
> => mw.l 0x3000004 0x55000000 <= wsize = rsize = 5 (2^5 = 32
> bytes)
> => mw.q 0x3000008 0x0 <= NextBytes = 0
> => mw.q 0x3000010 0x84000000 <= NextDestination = 0x84000000
> => mw.q 0x3000018 0x84001000 <= NextSource = 0x84001000
> => mw.l 0x84000000 0x87654321 <= Fill test data to dst
> => mw.l 0x84001000 0x12345678 <= Fill test data to src
> => md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
> 84000000: 87654321 !Ce.
> 84001000: 12345678 xV4.
> => md.l 0x3000000 8 <= Dump PDMA status
> 03000000: 00000001 55000000 00000000 00000000 .......U........
> 03000010: 84000000 00000000 84001000 00000000 ................
> => mw.l 0x3000000 0x3 <= Set channel 0 run and claim bits
> => md.l 0x3000000 8 <= Dump PDMA status
> 03000000: 40000001 55000000 00000000 00000000 [email protected]........
> 03000010: 84000000 00000000 84001000 00000000 ................
> => md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
> 84000000: 87654321 !Ce.
> 84001000: 12345678 xV4.
>
> Signed-off-by: Frank Chang <[email protected]>
> Tested-by: Max Hsu <[email protected]>
> Reviewed-by: Bin Meng <[email protected]>
> Tested-by: Bin Meng <[email protected]>
Thanks!
Applied to riscv-to-apply.next
Alistair
> ---
> hw/dma/sifive_pdma.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/hw/dma/sifive_pdma.c b/hw/dma/sifive_pdma.c
> index d7d2c53e97e..b4fd40573a5 100644
> --- a/hw/dma/sifive_pdma.c
> +++ b/hw/dma/sifive_pdma.c
> @@ -80,7 +80,7 @@ static void sifive_pdma_run(SiFivePDMAState *s, int ch)
>
> /* do nothing if bytes to transfer is zero */
> if (!bytes) {
> - goto error;
> + goto done;
> }
>
> /*
> @@ -135,11 +135,6 @@ static void sifive_pdma_run(SiFivePDMAState *s, int ch)
> s->chan[ch].exec_bytes -= remainder;
> }
>
> - /* indicate a DMA transfer is done */
> - s->chan[ch].state = DMA_CHAN_STATE_DONE;
> - s->chan[ch].control &= ~CONTROL_RUN;
> - s->chan[ch].control |= CONTROL_DONE;
> -
> /* reload exec_ registers if repeat is required */
> if (s->chan[ch].next_config & CONFIG_REPEAT) {
> s->chan[ch].exec_bytes = bytes;
> @@ -147,6 +142,11 @@ static void sifive_pdma_run(SiFivePDMAState *s, int ch)
> s->chan[ch].exec_src = src;
> }
>
> +done:
> + /* indicate a DMA transfer is done */
> + s->chan[ch].state = DMA_CHAN_STATE_DONE;
> + s->chan[ch].control &= ~CONTROL_RUN;
> + s->chan[ch].control |= CONTROL_DONE;
> return;
>
> error:
> --
> 2.25.1
>
>
