Stefan, Vinod,
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
On 2017-09-21 21:29, Peter Ujfalusi wrote:
>
>
> On 2017-09-21 20:17, Vinod Koul wrote:
>> On Sun, Sep 17, 2017 at 04:25:10PM +0200, Stefan Brüns wrote:
>>> The driver would happily accept buswidth of 16/32/64 bytes and program
>>> garbage to its registers.
>>
>> Peter?
>
> Well, eDMA as such has no limitation on the buswidth, the addr_width
> become ACNT, counter for the inner loop - which we use to represent the
> word length. In theory we could support 32K-1 long word with eDMA, which
> we actually do in case of memcpy.
>
> But the driver does state that it supports bus width of 1, 2, 3 and 4 bytes.
>
> These are form the past and I never felt the need to check them.
>
> I think it is fine to reject salve config when asking for longer dev
> width. I might revisit later if the need comes..
>
> Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
If it is not too late, I have second thoughts about this..
It might be better to remove the src_addr_width/dst_addr_width check
from edma_slave_config() and add all DMA_SLAVE_BUSWIDTH_* to
EDMA_DMA_BUSWIDTHS.
>
>>
>>>
>>> Signed-off-by: Stefan Brüns <stefan.bruens@xxxxxxxxxxxxxx>
>>> ---
>>> drivers/dma/edma.c | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
>>> index 3879f80a4815..c944ea339425 100644
>>> --- a/drivers/dma/edma.c
>>> +++ b/drivers/dma/edma.c
>>> @@ -887,8 +887,8 @@ static int edma_slave_config(struct dma_chan *chan,
>>> {
>>> struct edma_chan *echan = to_edma_chan(chan);
>>>
>>> - if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
>>> - cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
>>> + if (cfg->src_addr_width >= DMA_SLAVE_BUSWIDTH_8_BYTES ||
>>> + cfg->dst_addr_width >= DMA_SLAVE_BUSWIDTH_8_BYTES)
>>> return -EINVAL;
>>>
>>> memcpy(&echan->cfg, cfg, sizeof(echan->cfg));
>>> --
>>> 2.14.1
>>>
>>
>
> - Péter
>
- Péter
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