Re: [PATCH v3] dmaengine: pl330: flush before wait, and add dev burst support.
On Sun, Mar 11, 2018 at 11:01 AM, Vinod Koul wrote:
>
> sorry if it wasnt clear earlier, the lines below should come after the ---
> line. git-am skips that part while applying..
ok
>>
>> + /* do FLUSHP at beginning to clear any stale dma requests before the
>> + * first WFP.
>> + */
>
> multiline comments should be:
>
> /*
> * this is an example of multi-line
> * comment
> */
>
> Pls fix at this and other places...
ok
>
>> static inline int _ldst_memtodev(struct pl330_dmac *pl330,
>>unsigned dry_run, u8 buf[],
>> - const struct _xfer_spec *pxs, int cyc)
>> + const struct _xfer_spec *pxs, int cyc,
>> + enum pl330_cond cond)
>> {
>> int off = 0;
>> - enum pl330_cond cond;
>>
>> if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
>> cond = BURST;
>> - else
>> - cond = SINGLE;
>>
>> + /* do FLUSHP at beginning to clear any stale dma requests before the
>> + * first WFP.
>> + */
>> + if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
>> + off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
>> while (cyc--) {
>> 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], cond, pxs->desc->peri);
>> -
>> - if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
>> - off += _emit_FLUSHP(dry_run, &buf[off],
>> - pxs->desc->peri);
>> + if (cond == ALWAYS) {
>> + off += _emit_STP(dry_run, &buf[off], SINGLE,
>> + pxs->desc->peri);
>> + off += _emit_STP(dry_run, &buf[off], BURST,
>> + pxs->desc->peri);
>> + } else {
>> + off += _emit_STP(dry_run, &buf[off], cond,
>> + pxs->desc->peri);
>> + }
>
> this looks quite similar to previous routine above, if so can we please make
> it common function and invoke from both of these...
_ldst_memtodev and _ldst_devtomem are similar, but they were even more
similar before my patch. Do I really have to refactor existing code
to get my patch applied? I'm not trying to take over maintainership
of the pl330.c driver.
>
>> +static int _dregs(struct pl330_dmac *pl330, unsigned int dry_run, u8 buf[],
>> + const struct _xfer_spec *pxs, int transfer_length)
>> +{
>> + int off = 0;
>> + int dregs_ccr;
>> +
>> + if (transfer_length == 0)
>> + return off;
>> +
>> + switch (pxs->desc->rqtype) {
>> + case DMA_MEM_TO_DEV:
>> + off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs,
>> + transfer_length, SINGLE);
>> + break;
>
> empty line after each case pls
ok
>
>> + case DMA_DEV_TO_MEM:
>> + off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs,
>> + transfer_length, SINGLE);
>> + break;
>> + case DMA_MEM_TO_MEM:
>> + dregs_ccr = pxs->ccr;
>> + dregs_ccr &= ~((0xf << CC_SRCBRSTLEN_SHFT) |
>> + (0xf << CC_DSTBRSTLEN_SHFT));
>> + dregs_ccr |= (((transfer_length - 1) & 0xf) <<
>> + CC_SRCBRSTLEN_SHFT);
>> + dregs_ccr |= (((transfer_length - 1) & 0xf) <<
>> + CC_DSTBRSTLEN_SHFT);
>> + off += _emit_MOV(dry_run, &buf[off], CCR, dregs_ccr);
>> + off += _ldst_memtomem(dry_run, &buf[off], pxs, 1);
>> + break;
>> + default:
>> + off += 0x4000; /* Scare off the Client */
>
> Can you explain this bit, shouldnt this be err?
>
I just copied that behavior from the existing _bursts() function. I
guess the original author's idea was returning a big offset would
result in a dry run failure due to exceeding the maximum buffer size.
I do agree an error would be better, although it would require
refactoring since the return values from _bursts and _dregs are not
checked for errors, they just blindly add the return value to the
offset.
>> @@ -1303,11 +1362,6 @@ static int _setup_req(struct pl330_dmac *pl330,
>> unsigned dry_run,
>> /* DMAMOV CCR, ccr */
>> off += _emit_MOV(dry_run, &buf[off], CCR, pxs->ccr);
>>
>> - x = &pxs->desc->px;
>> - /* Error if xfer length is not aligned at burst size */
>> - if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr)))
>> - return -EINVAL;
>> -
>> off += _setup_xfer(pl330, dry_run, &buf[off], pxs);
>>
>> /* DMASEV peripheral/event */
>> @@ -2115,15 +2169,29 @@ static int pl330_config(struct dma_chan *chan,
>> pch->fifo_addr = slave_config->dst_addr;
>> if (slave_config->dst_addr_width)
>>
Re: [PATCH v3] dmaengine: pl330: flush before wait, and add dev burst support.
On Tue, Mar 06, 2018 at 11:03:22AM -0500, Frank Mori Hess wrote:
> Do DMAFLUSHP _before_ the first DMAWFP to ensure controller
> and peripheral are in agreement about dma request state before first
> transfer. Add support for burst transfers to/from peripherals. In the new
> scheme, the controller does as many burst transfers as it can then
> transfers the remaining dregs with either single transfers for
> peripherals, or with a reduced size burst for memory-to-memory transfers.
>
> Signed-off-by: Frank Mori Hess
> Tested-by: Frank Mori Hess
sorry if it wasnt clear earlier, the lines below should come after the ---
line. git-am skips that part while applying..
>
> I tested dma transfers to peripherals with designware serial port
> (drivers/tty/serial/8250/8250_dw.c) and a GPIB interface
> (https://github.com/fmhess/fmh_gpib_core). I tested memory-to-memory
> transfers using the dmatest module.
>
> v3 of this patch should be the same as v2 except with checkpatch.pl
> warnings and errors cleaned up.
>
> ---
> drivers/dma/pl330.c | 146
> +---
> 1 file changed, 104 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index d7327fd5f445..cc2e4456bec1 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -1094,26 +1094,33 @@ static inline int _ldst_memtomem(unsigned dry_run, u8
> buf[],
> return off;
> }
>
> -static inline int _ldst_devtomem(struct pl330_dmac *pl330, unsigned dry_run,
> - u8 buf[], const struct _xfer_spec *pxs,
> - int cyc)
> +static inline int _ldst_devtomem(struct pl330_dmac *pl330,
> + unsigned int dry_run, u8 buf[],
> + const struct _xfer_spec *pxs,
> + int cyc, enum pl330_cond cond)
> {
> int off = 0;
> - enum pl330_cond cond;
>
> if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
> cond = BURST;
> - else
> - cond = SINGLE;
>
> + /* do FLUSHP at beginning to clear any stale dma requests before the
> + * first WFP.
> + */
multiline comments should be:
/*
* this is an example of multi-line
* comment
*/
Pls fix at this and other places...
> static inline int _ldst_memtodev(struct pl330_dmac *pl330,
>unsigned dry_run, u8 buf[],
> - const struct _xfer_spec *pxs, int cyc)
> + const struct _xfer_spec *pxs, int cyc,
> + enum pl330_cond cond)
> {
> int off = 0;
> - enum pl330_cond cond;
>
> if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
> cond = BURST;
> - else
> - cond = SINGLE;
>
> + /* do FLUSHP at beginning to clear any stale dma requests before the
> + * first WFP.
> + */
> + if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
> + off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
> while (cyc--) {
> 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], cond, pxs->desc->peri);
> -
> - if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
> - off += _emit_FLUSHP(dry_run, &buf[off],
> - pxs->desc->peri);
> + if (cond == ALWAYS) {
> + off += _emit_STP(dry_run, &buf[off], SINGLE,
> + pxs->desc->peri);
> + off += _emit_STP(dry_run, &buf[off], BURST,
> + pxs->desc->peri);
> + } else {
> + off += _emit_STP(dry_run, &buf[off], cond,
> + pxs->desc->peri);
> + }
this looks quite similar to previous routine above, if so can we please make
it common function and invoke from both of these...
> +static int _dregs(struct pl330_dmac *pl330, unsigned int dry_run, u8 buf[],
> + const struct _xfer_spec *pxs, int transfer_length)
> +{
> + int off = 0;
> + int dregs_ccr;
> +
> + if (transfer_length == 0)
> + return off;
> +
> + switch (pxs->desc->rqtype) {
> + case DMA_MEM_TO_DEV:
> + off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs,
> + transfer_length, SINGLE);
> + break;
empty line after each case pls
> + case DMA_DEV_TO_MEM:
> + off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs,
> + transfer_length, SINGLE);
> + break;
> + case DMA_MEM_TO_MEM:
> + dregs_ccr = pxs->ccr;
> + dregs_ccr &= ~((0xf << CC_SRCBRSTLEN_SHFT) |
> + (0xf << CC_DSTBRSTLEN_SHFT));
> + dregs_ccr |= (((transfer_lengt
