[PATCH v2 0/6] dmaengine: ti: k3-udma: Fixes for 5.6

Peter Ujfalusi
2020-02-14T09:14:44Z

Hi Vinod,

Recently we have uncovered silicon and driver issues which was not addressed in
the initial driver:

1. RX channel teardown will lock up the channel if we have stale data
in the DMA FIFOs and we don't have active transfer (no descriptor for UDMA).
The workaround is to use a dummy drain packet in these cases.

2. Early TX completion handling
The delayed work approach was not working efficiently causing the UART, SPI
performance to degrade, with the patch from Vignesh we see 10x performance
increase

3. TR setup for slave_sg
It was possible that the sg_len() was not multiple of 'burst * dev_width' and
because of this we ended up with incorrect TR setups.
Using a single function for TR setup makes things simpler and error prone among
slave_sg, cyclic and memcpy

4. Pause/Resume causes kernel crash
if it was called when we did not had active transfer the uc->desc was NULL.

5. The terminated cookie was never marked as completed
client will think that it is still in progress, which is not the case.
Also adding back the check for running channel in tx_status since if the channel
is not running then it implies that it has been terminated, so no transfer is
running.

Regards,
Peter
---
Peter Ujfalusi (5):
dmaengine: ti: k3-udma: Workaround for RX teardown with stale data in
peer
dmaengine: ti: k3-udma: Move the TR counter calculation to helper
function
dmaengine: ti: k3-udma: Use the TR counter helper for slave_sg and
cyclic
dmaengine: ti: k3-udma: Use the channel direction in pause/resume
functions
dmaengine: ti: k3-udma: Fix terminated transfer handling

Vignesh Raghavendra (1):
dmaengine: ti: k3-udma: Use ktime/usleep_range based TX completion
check

drivers/dma/ti/k3-udma.c | 493 ++++++++++++++++++++++++++++-----------
1 file changed, 361 insertions(+), 132 deletions(-)