On 23.01.2019 18:33, Codrin Ciubotariu - M19940 wrote:

From: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>

atchan->status variable is used to store two different information:
  - pass channel interrupts status from interrupt handler to tasklet;
  - channel information like whether it is cyclic or paused;

This causes a bug when device_terminate_all() is called,
(AT_XDMAC_CHAN_IS_CYCLIC cleared on atchan->status) and then a late End
of Block interrupt arrives (AT_XDMAC_CIS_BIS), which sets bit 0 of
atchan->status. Bit 0 is also used for AT_XDMAC_CHAN_IS_CYCLIC, so when
a new descriptor for a cyclic transfer is created, the driver reports
the channel as in use:

if (test_and_set_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status)) {
	dev_err(chan2dev(chan), "channel currently used\n");
	return NULL;
}

This patch fixes the bug by adding a different struct member to keep
the interrupts status separated from the channel status bits.

Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
---

Forgot to add:

Changes in v2:
  - changed commit message;

If you need v3 for this let me know.

Best regards,
Codrin

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