Re: Why is the max_sectors set the 240

From: Alan Stern
Date: Sat Sep 24 2016 - 09:54:29 EST

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

Alan Stern