From: Alistair Francis <alistair23@gmail.com>
To: Frank Chang <frank.chang@sifive.com>
Cc: "open list:RISC-V" <qemu-riscv@nongnu.org>,
Bin Meng <bin.meng@windriver.com>,
"qemu-devel@nongnu.org Developers" <qemu-devel@nongnu.org>,
Max Hsu <max.hsu@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>,
Alistair Francis <Alistair.Francis@wdc.com>,
Bin Meng <bmeng.cn@gmail.com>
Subject: Re: [PATCH RESEND v2 4/4] hw/dma: sifive_pdma: don't set Control.error if 0 bytes to transfer
Date: Tue, 14 Sep 2021 12:24:34 +1000 [thread overview]
Message-ID: <CAKmqyKMY_7jJ2g9Te8JRPD0dwMP_y1WPnjZkKc5Fj+iJhWiRig@mail.gmail.com> (raw)
In-Reply-To: <20210912130553.179501-5-frank.chang@sifive.com>
On Sun, Sep 12, 2021 at 11:11 PM <frank.chang@sifive.com> wrote:
>
> From: Frank Chang <frank.chang@sifive.com>
>
> 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 ...@...U........
> 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 <frank.chang@sifive.com>
> Tested-by: Max Hsu <max.hsu@sifive.com>
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
> Tested-by: Bin Meng <bmeng.cn@gmail.com>
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
>
>
prev parent reply other threads:[~2021-09-14 2:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-12 13:05 [PATCH RESEND v2 0/4] hw/dma: Align SiFive PDMA behavior with real hardware frank.chang
2021-09-12 13:05 ` [PATCH RESEND v2 1/4] hw/dma: sifive_pdma: reset Next* registers when Control.claim is set frank.chang
2021-09-12 13:05 ` [PATCH RESEND v2 2/4] hw/dma: sifive_pdma: claim bit must be set before DMA transactions frank.chang
2021-09-12 13:05 ` [PATCH RESEND v2 3/4] hw/dma: sifive_pdma: allow non-multiple transaction size transactions frank.chang
2021-09-12 13:05 ` [PATCH RESEND v2 4/4] hw/dma: sifive_pdma: don't set Control.error if 0 bytes to transfer frank.chang
2021-09-14 2:24 ` Alistair Francis [this message]
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