From: Benjamin Herrenschmidt <benh@kernel•crashing.org>
To: Eugene Surovegin <ebs@ebshome•net>
Cc: linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH] powerpc/hvsi: increase handshake timeout from 200ms to 400ms.
Date: Tue, 27 Aug 2013 10:52:40 +1000 [thread overview]
Message-ID: <1377564760.3819.91.camel@pasglop> (raw)
In-Reply-To: <1377543212-20432-1-git-send-email-ebs@ebshome.net>
On Mon, 2013-08-26 at 11:53 -0700, Eugene Surovegin wrote:
> This solves a problem observed in kexec'ed kernel where 200ms timeout is
> too short and bootconsole fails to initialize. Console did eventually
> become workable but much later into the boot process.
>
> Observed timeout was around 260ms, but I decided to make it a little bigger
> for more reliability.
>
> This has been tested on Power7 machine with Petitboot as a primary
> bootloader and PowerNV firmware.
Thanks !
I've been carrying a patch like that in my test stuff, the only reason I
hadn't merged it yet was that I though there might be a problem under
the hood, such as us maybe not actually polling the FSP fast enough or
something, but so far it looks like it's just slow to respond.
Cheers,
Ben.
> Signed-off-by: Eugene Surovegin <surovegin@google•com>
> ---
> drivers/tty/hvc/hvsi_lib.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/hvc/hvsi_lib.c b/drivers/tty/hvc/hvsi_lib.c
> index 3396eb9..ac27671 100644
> --- a/drivers/tty/hvc/hvsi_lib.c
> +++ b/drivers/tty/hvc/hvsi_lib.c
> @@ -341,8 +341,8 @@ void hvsilib_establish(struct hvsi_priv *pv)
>
> pr_devel("HVSI@%x: ... waiting handshake\n", pv->termno);
>
> - /* Try for up to 200s */
> - for (timeout = 0; timeout < 20; timeout++) {
> + /* Try for up to 400ms */
> + for (timeout = 0; timeout < 40; timeout++) {
> if (pv->established)
> goto established;
> if (!hvsi_get_packet(pv))
prev parent reply other threads:[~2013-08-27 0:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-26 18:53 [PATCH] powerpc/hvsi: increase handshake timeout from 200ms to 400ms Eugene Surovegin
2013-08-27 0:52 ` Benjamin Herrenschmidt [this message]
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