linux-kernel - Re: Why is the max

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>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.44L0.1609240950010.15129-100000@netrider.rowland.org>
Date:   Sat, 24 Sep 2016 09:54:22 -0400 (EDT)
From:   Alan Stern <stern@...land.harvard.edu>
To:     Lipengcheng <lpc.li@...ilicon.com>
cc:     "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        Mathias Nyman <mathias.nyman@...el.com>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "usb-storage@...ts.one-eyed-alien.net" 
        <usb-storage@...ts.one-eyed-alien.net>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Fangzhuanghai <fangzhuanghai@...ilicon.com>,
        Caizhiyong <caizhiyong@...ilicon.com>
Subject: Re: Why is the max_sectors set the 240

On Sat, 24 Sep 2016, Lipengcheng wrote:

> Hi,
> Some special superspeed u3 disk connect xhci control. Then the u3
> disk is read/write and has the Transfer error on endpoint
> (COMP_TX_ERR) error. However in the pc windows does not have the
> problem.By analysis, the windows is each transfer 64K size. The Linux
> is 120K size. In the scsiglue.c, the max_sectors value set the 128
> and each transfer 64K size. Then the Linux system is no problem too.
> Why is the max_sectors set the 240?  May the max_sectors be the other
> values?

Most devices work okay with max_sectors set to 240.  However, you can 
change the value if you want.  Read the usb-storage.quirks section in 
Documentation/kernel-parameters.txt; the m flag will set max_sectors to 
64.

Alan Stern