From ae000c5f658d3636ebf19b7a8c819dce618780c4 Mon Sep 17 00:00:00 2001 From: Frank Chang Date: Sun, 12 Sep 2021 21:05:48 +0800 Subject: [PATCH] hw/dma: sifive_pdma: don't set Control.error if 0 bytes to transfer 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 Tested-by: Max Hsu Reviewed-by: Bin Meng Tested-by: Bin Meng Message-id: 20210912130553.179501-5-frank.chang@sifive.com Signed-off-by: Alistair Francis --- 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 d7d2c53e97..b4fd40573a 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: