From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 786A12C0082 for ; Tue, 27 Aug 2013 10:53:02 +1000 (EST) Message-ID: <1377564760.3819.91.camel@pasglop> Subject: Re: [PATCH] powerpc/hvsi: increase handshake timeout from 200ms to 400ms. From: Benjamin Herrenschmidt To: Eugene Surovegin Date: Tue, 27 Aug 2013 10:52:40 +1000 In-Reply-To: <1377543212-20432-1-git-send-email-ebs@ebshome.net> References: <1377543212-20432-1-git-send-email-ebs@ebshome.net> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 > --- > 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))