Re: [PATCH 1/5] DMA: pl330: support burst mode for dev-to-mem and mem-to-dev transmit

From: Krzysztof Kozlowski
Date: Thu Aug 27 2015 - 08:58:03 EST


2015-08-27 17:48 GMT+09:00 Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>:
>
> This patch adds to support burst mode for dev-to-mem and
> mem-to-dev transmit.
>
> Signed-off-by: Boojin Kim <boojin.kim@xxxxxxxxxxx>
> Signed-off-by: Addy Ke <addy.ke@xxxxxxxxxxxxxx>
> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> cc: Heiko Stuebner <heiko@xxxxxxxxx>
> cc: Doug Anderson <dianders@xxxxxxxxxxxx>
> cc: Olof Johansson <olofj@xxxxxxxxxx>
> Reviewed-and-tested-by: Sonny Rao <sonnyrao@xxxxxxxxxxxx>

For the entire patchset: I would prefer to see someone's
reviewed/tested tag in his response. Sending a version 1 of patchset
(regardless of Boojin Kim's work two years ago) with such tag could
mean anything. I cannot verify it easily (unless digging somewhere...
or asking people). You could add for example: Reviewed-by Santa Claus.
Should I sent a letter to him asking for confirmation? :)

More seriously - reviewed-by is a statement (please look at
Documentation/SubmittingPatches) and you cannot force someone to make
that statement. He must make such statement on his own.

That's all from my side since I don't feel skilled enough to review the code.

Best regards,
Krzysztof

>
> ---
>
> drivers/dma/pl330.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index ecab4ea0..0d544d2 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -1141,10 +1141,13 @@ static inline int _ldst_devtomem(unsigned dry_run, u8 buf[],
> const struct _xfer_spec *pxs, int cyc)
> {
> int off = 0;
> + enum pl330_cond cond;
> +
> + cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
>
> while (cyc--) {
> - off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> - off += _emit_LDP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> + off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
> + off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_ST(dry_run, &buf[off], ALWAYS);
> off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
> }
> @@ -1156,11 +1159,14 @@ static inline int _ldst_memtodev(unsigned dry_run, u8 buf[],
> const struct _xfer_spec *pxs, int cyc)
> {
> int off = 0;
> + enum pl330_cond cond;
> +
> + cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
>
> while (cyc--) {
> - off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> + off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_LD(dry_run, &buf[off], ALWAYS);
> - off += _emit_STP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> + off += _emit_STP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
> }
>
> @@ -2557,7 +2563,7 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
>
> desc->rqtype = direction;
> desc->rqcfg.brst_size = pch->burst_sz;
> - desc->rqcfg.brst_len = 1;
> + desc->rqcfg.brst_len = pch->burst_len;
> desc->bytes_requested = period_len;
> fill_px(&desc->px, dst, src, period_len);
>
> @@ -2702,7 +2708,7 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
> }
>
> desc->rqcfg.brst_size = pch->burst_sz;
> - desc->rqcfg.brst_len = 1;
> + desc->rqcfg.brst_len = pch->burst_len;
> desc->rqtype = direction;
> desc->bytes_requested = sg_dma_len(sg);
> }
> --
> 2.3.7
>
>
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