linux-kernel - why we need a msleep(5) in ehci_bus

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Mon, 13 May 2013 14:17:20 +0800
From:	linux fddl <fddllinux@...il.com>
To:	stern@...land.harvard.edu, linux-usb@...r.kernel.org,
	gregkh@...e.de
Cc:	linux-kernel@...r.kernel.org
Subject: why we need a msleep(5) in ehci_bus_suspend/resume

Hi,

  From the ehci-hub.c, I find that ehci_bus_suspend/resume have some
code like this:

if (time_before(jiffies, ehci->netx_statechange))
    msleep(5);
...
ehci->next_statechange = jiffies + msec_to_jiffies(10);

and

if (time_before(jiffies, ehci->netx_statechange))
    msleep(5);
...
ehci->next_statechange = jiffies + msec_to_jiffies(5);

but I don't know why such a short sleep is needed, and why one is
[ehci->next_statechange = jiffies + msec_to_jiffies(10)] and the other is
[ehci->next_statechange = jiffies + msec_to_jiffies(5)],
I googled for a long time, but it seems that there is no explanation.

  Anyone knows why and can give any explanation?

  Thanks very much!

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