Re: [GIT PATCH] W1 patches for 2.6.13

[Evgeniy Polyakov <johnpol@2ka.mipt.ru>]

On Fri, Sep 09, 2005 at 02:16:19PM -0700, GregKH (greg@kroah.com) wrote:
> On Fri, Sep 09, 2005 at 09:08:25AM +0400, Evgeniy Polyakov wrote:
> > On Thu, Sep 08, 2005 at 08:30:36PM -0700, Greg KH (gregkh@suse.de) wrote:
> > > On Fri, Sep 09, 2005 at 01:30:09AM +0200, Marcel Holtmann wrote:
> > > > Hi Greg,
> > > > 
> > > > > Here are some w1 patches that have been in the -mm tree for a while.
> > > > > They add a new driver, and fix up the netlink logic a lot.  They also
> > > > > add a crc16 implementation that is needed.
> > > > 
> > > > adding the CRC-16 is very cool. I was just about to submit one by my
> > > > own, because it is also needed for the Bluetooth L2CAP retransmission
> > > > and flow control support.
> > > > 
> > > > What about the 1-Wire notes inside the CRC-16 code. This suppose to be
> > > > generic code and so this doesn't belong there.
> > > 
> > > Yes, those comments don't belong there.  Evgeniy, want to fix this?
> > 
> > No problem. Patch attached.
> > 
> > > thanks,
> > > 
> > > greg k-h
> > 
> > Remove w1 specific comments from generic crc16 implementation.
> > 
> > Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
> > 
> > diff --git a/include/linux/crc16.h b/include/linux/crc16.h
> > --- a/include/linux/crc16.h
> > +++ b/include/linux/crc16.h
> > @@ -1,22 +1,11 @@
> >  /*
> >   *	crc16.h - CRC-16 routine
> >   *
> > - * Implements the standard CRC-16, as used with 1-wire devices:
> > + * Implements the standard CRC-16:
> >   *   Width 16
> >   *   Poly  0x8005 (x^16 + x^15 + x^2 + 1)
> >   *   Init  0
> >   *
> > - * For 1-wire devices, the CRC is stored inverted, LSB-first
> > - *
> > - * Example buffer with the CRC attached:
> > - *   31 32 33 34 35 36 37 38 39 C2 44
> > - *
> > - * The CRC over a buffer with the CRC attached is 0xB001.
> > - * So, if (crc16(0, buf, size) == 0xB001) then the buffer is valid.
> > - *
> > - * Refer to "Application Note 937: Book of iButton Standards" for details.
> > - * http://www.maxim-ic.com/appnotes.cfm/appnote_number/937
> > - *
> >   * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
> >   *
> >   * This source code is licensed under the GNU General Public License,
> > @@ -28,9 +17,6 @@
> >  
> >  #include <linux/types.h>
> >  
> > -#define CRC16_INIT		0
> > -#define CRC16_VALID		0xb001
> > -
> 
> This breaks your w1 code:
> 	    CC [M]  drivers/w1/w1_ds2433.o
> 	  drivers/w1/w1_ds2433.c: In function `w1_f23_refresh_block':
> 	  drivers/w1/w1_ds2433.c:84: error: `CRC16_INIT' undeclared (first use in this function)
> 	  drivers/w1/w1_ds2433.c:84: error: (Each undeclared identifier is reported only once
> 	  drivers/w1/w1_ds2433.c:84: error: for each function it appears in.)
> 	  drivers/w1/w1_ds2433.c:84: error: `CRC16_VALID' undeclared (first use in this function)
> 	  drivers/w1/w1_ds2433.c: In function `w1_f23_write_bin':
> 	  drivers/w1/w1_ds2433.c:224: error: `CRC16_INIT' undeclared (first use in this function)
> 	  drivers/w1/w1_ds2433.c:224: error: `CRC16_VALID' undeclared (first use in this function)
> 
> 
> So I'm not going to apply this :(

I'm sorry - quite far from testing machines...
Here is additional patch for ds_2433.c - it adds two missing defines.

--- ./drivers/w1/w1_ds2433.c.orig	2005-09-10 01:59:41.000000000 +0400
+++ ./drivers/w1/w1_ds2433.c	2005-09-10 01:57:41.000000000 +0400
@@ -15,6 +15,10 @@
 #include <linux/delay.h>
 #ifdef CONFIG_W1_F23_CRC
 #include <linux/crc16.h>
+
+#define CRC16_INIT		0
+#define CRC16_VALID		0xb001
+
 #endif
 
 #include "w1.h"

> thanks,
> 
> greg k-h

-- 
	Evgeniy Polyakov