Re: [PATCH v5 3/4] serial: sh-sci: Fix fallback to PIO in sci_dma_rx_complete()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Jan 07, 2019 at 05:23:19PM +0100, Geert Uytterhoeven wrote:
> When submitting a DMA request fails in sci_dma_rx_complete(), the driver
> tries to fall back to PIO, but that does not work: no more data will be
> received, or the kernel will even crash.
> 
> Fix this similar as in (but not identical to) sci_submit_rx():
>   - On SCIF, PIO cannot take over if any DMA transactions are pending,
>     hence they must be terminated first.
>   - All active cookies must be invalidated, else rx_timer_fn() may
>     trigger a NULL pointer dereference.
>   - Restarting the port is not needed, as it is already running, but
>     serial port interrupts must be directed back from the DMA engine to
>     the CPU.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>




[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux