Re: [RFC] With 8250 Designware UART, if writes to the LCR failed the kernel will hung up

[Alan Cox]

On Mon, 2015-03-09 at 07:36 -0700, Tim Kryger wrote:
> On Mon, Mar 9, 2015 at 6:32 AM, Alan Cox <alan@xxxxxxxxxxxxxxx> wrote:
> >> Maybe the next release of the board we will upgrade the serial block to the new version.
> >> but the issue is that how we circumvent this problem in kernel?
> >
> > What is the official vendor workaround ?
> 
> They introduced a UART_16550_COMPATIBLE option for the IP which should
> be selected.
> 
> If configured, writes to the LCR are allowed even if it is "busy" so
> there is no need to retry.
> 
> More importantly there is no possibility of failing to write the LCR
> after numerous retries.


Ah no - I meant what is their official software workaround for existing
parts with the bug ? Presumably they have an errata document that
discusses this and the correct methods they recommend to avoid the
hang ?

Alan


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/