[PATCH 0/4] dmaengine: dw: Fix src/dst addr width misconfig

[Serge Semin]

The main goal of this series is to fix the data disappearance in case of
the DW UART handled by the DW AHB DMA engine. The problem happens on a
portion of the data received when the pre-initialized DEV_TO_MEM
DMA-transfer is paused and then disabled. The data just hangs up in the
DMA-engine FIFO and isn't flushed out to the memory on the DMA-channel
suspension (see the second commit log for details). On a way to find the
denoted problem fix it was discovered that the driver doesn't verify the
peripheral device address width specified by a client driver, which in its
turn if unsupported or undefined value passed may cause DMA-transfer being
misconfigured. It's fixed in the first patch of the series.

In addition to that two cleanup patch follow the fixes described above in
order to make the DWC-engine configuration procedure more coherent. First
one simplifies the CTL_LO register setup methods. Second one simplifies
the max-burst calculation procedure and unifies it with the rest of the
verification methods. Please see the patches log for more details.

Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jiri Slaby <jirislaby@xxxxxxxxxx>
Cc: dmaengine@xxxxxxxxxxxxxxx
Cc: linux-serial@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Serge Semin (4):
  dmaengine: dw: Add peripheral bus width verification
  dmaengine: dw: Add memory bus width verification
  dmaengine: dw: Simplify prepare CTL_LO methods
  dmaengine: dw: Simplify max-burst calculation procedure

 drivers/dma/dw/core.c   | 97 ++++++++++++++++++++++++++++++++++++-----
 drivers/dma/dw/dw.c     | 43 +++++++++++-------
 drivers/dma/dw/idma32.c | 25 +++++++----
 drivers/dma/dw/regs.h   |  1 -
 4 files changed, 129 insertions(+), 37 deletions(-)

-- 
2.43.0