Re: [PATCH v2] dmaengine: at_xdmac: Fix wrongfull report of a channel as in use

From: Vinod Koul
Date: Sat Feb 02 2019 - 05:27:23 EST

On 23-01-19, 16:33, Codrin.Ciubotariu@xxxxxxxxxxxxx wrote:
> From: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
> 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.

Applied, thanks