From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Babic Date: Wed, 25 Jul 2012 11:58:36 +0200 Subject: [U-Boot] [PATCH] net: Improve the speed of netconsole In-Reply-To: <1343160675-30148-1-git-send-email-joe.hershberger@ni.com> References: <1343160675-30148-1-git-send-email-joe.hershberger@ni.com> Message-ID: <500FC34C.2020703@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 24/07/2012 22:11, Joe Hershberger wrote: > Previously u-boot would initialize the network interface for every > network operation and then shut it down again. This makes sense for > most operations where the network in not known to be needed soon after > the operation is complete. In the case of netconsole, it will use the > network for every interaction with the shell or every printf. This > means that the network is being reinitialized very often. On many > devices, this intialization is very slow. Hi Joe, agree with you - and in some cases, such as ethernet on USB, netconsole is not yet useful. Which is the status of the ethernet controller before starting the kernel ? Up now we guarantee that the hardware is turned off before kernel takes over. This patch changes this behavior, and I know from the past (really with USB, we have a usb_stop before calling the kernel) that this can be dangerous. Maybe you can add a eth_halt() call into do_bootm(). Second general question is if the behavior of CONFIG_NETCONSOLE_PERSIST_ETH should be always turned on when Netconsole is activated. I mean, your patch maintain a high compatibility with the past, but I suppose that everyone using netconsole likes the new behavior that you are introducing and everyone will turn CONFIG_NETCONSOLE_PERSIST_ETH on. Then we can simply use CONFIG_NETCONSOLE as switch. Best regards, Stefano -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de =====================================================================