linux-kernel - Re: Regarding USB-to-serial device driver

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] [thread-next>] [day] [month] [year] [list]

Message-Id: <20100923100127.M64470@admin-gateway.ncra.tifr.res.in>
Date:	Thu, 23 Sep 2010 15:45:52 +0530
From:	"Raju Rameshwar Uprade" <rajsingh@...a.tifr.res.in>
To:	Greg KH <gregkh@...e.de>,
	Raju Rameshwar Uprade <rajsingh@...a.tifr.res.in>
Cc:	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org
Subject: Re: Regarding USB-to-serial device driver

> For what driver?

  I am using pl2303.c ( USB to serial device driver ) to communicate to various devices
connected in parallel using RS-485 interface card.

> > Kindly help me.I am facing the problem in separating the data bytes so
> > that I can send the data bytes separately using usb_submit_urb.
> 
> It all depends on the driver you are using.  Why not do all of this from
> userspace?  That way it works on any device you are talking to.

I want to write data twice :

1. Only address byte and then 
2. Data bytes.

I am properly allocating memory for write_urb using kzalloc.When I write complete user
buffer to the port, it send the data properly.

But when I try to write only address byte machine get hang.

I have attached the source file.

Thanks,
 Raj.

View attachment "pl2303_mcm.c" of type "text/x-csrc" (34224 bytes)