[PATCH v4 20/25] dmaengine: edma: Simplify the interrupt handling
Peter Ujfalusi
peter.ujfalusi at ti.com
Wed Oct 14 04:16:06 PDT 2015
On 10/14/2015 02:12 PM, Peter Ujfalusi wrote:
>>> + } else if (edma_read(ecc, EDMA_QEMR)) {
>>> + dev_dbg(ecc->dev, "QEMR %02x\n",
>>> + edma_read(ecc, EDMA_QEMR));
>>> + for (i = 0; i < 8; i++) {
>>> + if (edma_read(ecc, EDMA_QEMR) & BIT(i)) {
>>> + /* Clear the corresponding IPR bits */
>>> + edma_write(ecc, EDMA_QEMCR, BIT(i));
>>> + edma_shadow0_write(ecc, SH_QSECR,
>>> + BIT(i));
>>> +
>>> + /* NOTE: not reported!! */
>>
>> what does this mean?
>
> For QEMR and CCERR registers the Linux driver only acks the event, but do not
> do anything.
> In Linux we are not using the qDMA of the eDMA3 and there is not much we can
> do when the CCERR happens.
> Hrm, probably moving the CCERR print to dev_err() might be useful, but again I
> have not seen this happen. But if it does, we need to come up with something
> to avoid it. Basically repartition the use of Transfer Controllers, but this
> can not be done with this stack. An upcoming series will give us ways to fine
> tune the use of TCs.
In the interrupt handler simplification patch I move the CCERR to dev_warn()
so I leave it like this for this patch - as the function has been just moved
down in the code to be able to call the actual handler of the events.
--
Péter
More information about the linux-arm-kernel
mailing list