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

From: Andy Shevchenko
Date: Tue Apr 16 2024 - 15:13:42 EST


On Tue, Apr 16, 2024 at 07:28:54PM +0300, Serge Semin wrote:
> 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.

Thank you for this.
I have looked into all of them and most worrying (relatively to the rest) to me
is the second patch that does some tricks. The rest are the cosmetics that can
be easily addressed.

--
With Best Regards,
Andy Shevchenko