linux-kernel - Re: [tpmdd-devel] [PATCH 1/1] TPM: STMicroelectronics ST33 I2C KERNEL 3.x.x

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Message-ID: <20121205171350.GD21050@ennui.austin.ibm.com>
Date:	Wed, 5 Dec 2012 11:13:51 -0600
From:	Kent Yoder <key@...ux.vnet.ibm.com>
To:	Mathias LEBLANC <Mathias.LEBLANC@...com>
Cc:	Peter Hüwe <PeterHuewe@....de>,
	Kent Yoder <shpedoikal@...il.com>,
	Jean-Luc BLANC <jean-luc.blanc@...com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Rajiv Andrade <mail@...jiv.net>,
	"tpmdd-devel@...ts.sourceforge.net" 
	<tpmdd-devel@...ts.sourceforge.net>,
	"Sirrix@...per.es" <Sirrix@...per.es>
Subject: Re: [tpmdd-devel] [PATCH 1/1] TPM: STMicroelectronics ST33 I2C
 KERNEL 3.x.x

On Wed, Dec 05, 2012 at 05:11:40PM +0100, Mathias LEBLANC wrote:
> Hi Peter,
> 
> Thanks for your contribution.
> I have modified the driver files name and descriptions.
> Regarding the warnings, it's strange. 
> 
> @Kent, could you confirm that you have the same?

  Yep, I see these too. They're a side effect of storing the i2c_client
pointer in vendor->iobase, which is __iomem.  The i2c_client struct
isn't __iomem at all though, writes in the i2c subsystem are done
through client->addr.  So i2c_client should really be stored somewhere
else, no?

  vendor->data seems like the right place.  I'm on the hook to update
the other drivers with a macro for accessing vendor->data in tpm.h.
I'll make these updates and send out a patch.

Kent

> Regards,
> 
> Mathias Leblanc
> 
> -----Original Message-----
> From: Peter Hüwe [mailto:PeterHuewe@....de] 
> Sent: 29 November, 2012 01:05
> To: Mathias LEBLANC
> Cc: Kent Yoder; Kent Yoder; Jean-Luc BLANC; linux-kernel@...r.kernel.org; Rajiv Andrade; tpmdd-devel@...ts.sourceforge.net; Sirrix@...per.es
> Subject: Re: [tpmdd-devel] [PATCH 1/1] TPM: STMicroelectronics ST33 I2C KERNEL 3.x.x
> 
> Hi Mathias,
> 
> please note: 
> I'm writing this email on behalf of myself only and nobody else, especially not my employer - and I'm doing this in my spare time.
> I'm working for a direct competitor of yours, but I'm not using any knowledge that I've picked up at work or that is considered secret in any way.
> I have a personal interest in the TPM subsystem and want to keep it as clean as possible.
> So please don't see my review as something negative, but rather something positive.
> 
> 
> Am Mittwoch, 28. November 2012, 18:48:57 schrieb Mathias LEBLANC:
> > Ok, so i have patch the ST33 I2C driver on this branch and correct 
> > some errors. I send you the patch for the kernel 3.x I have no error 
> > on compilation, tell me if you have problems.
> > I have implemented the tpm_do_selftest function to get the tpm ready, 
> > but it can be removed ________________________________________
> 
> Unfortunately you attached the patch instead of sending it in plaintext which is the usual practice -> care to resend in plain text? 
> Makes the review far easier.
> 
> (btw.: Please also have a look at
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/SubmittingPatches;hb=HEAD
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/SubmitChecklist;hb=HEAD
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/SubmittingDrivers;hb=HEAD
> which describes the process in detail)
> 
> When you resend the patch, can you please include the "metadata" as well - i.e. your modifications to the Kconfig / Makefile etc.
> I do not see a reason why to keep it in a seperate patch.
> 
> 
> 
> 
> I tried the patch you've posted and it applies cleanly and now (finally) compiles as well - so now I can start with my review:
> 
> = The name =
> There's already one i2c tpm driver in the tree, so maybe it would be a good idea to keep the naming scheme consistent? 
> -> How about tpm_i2c_stm_st33.c ?
> Eventually this is something Kent as a maintainer has to decice - but I would really like to see the name change.
> I hope we can eventually consolidate all the 'tis' based drivers.
> 
> 
> = Compiling / License =
> When compiling the driver I get the following warning
>    WARNING: modpost: missing MODULE_LICENSE() in /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.o
> Please include the appropriate MODULE_LICENSE as my kernel otherwise gets tainted by your driver.
> 
> Also this:
> + * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24
> + * Copyright (C) 2009, 2010  STMicroelectronics
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> 
> is not possible afaik - kernel code must be under GPL v2 _only_ without the "or (at your option) any later version." addition.
> 
> 
> 
> = sparse warnings =
> When running sparse against your code I get the following warnings:
>  make -C /data/data-old/linux-2.6/ M=`pwd`  modules C=1
> make: Entering directory `/data/data-old/linux-2.6'
>   CHECK   /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:167:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:187:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:180:5: warning: symbol 'wait_for_serirq_timeout' was not declared. Should it be static?
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:210:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:227:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:245:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:269:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:307:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:324:38: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:394:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:424:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:456:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:531:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:672:29: warning: incorrect type in assignment (different address spaces)
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:672:29:    expected void [noderef] <asn:2>*iobase
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:672:29:    got struct i2c_client *client
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:781:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:818:19: warning: cast removes address space of expression
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:841:19: warning: cast removes address space of expression
>   CC [M]  /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.o
>   Building modules, stage 2.
>   MODPOST 8 modules
> 
> 
> Please fix these if applicable - otherwise you'll probably get a friendly reminder to do so by fengguang's build test ;)
> 
> 
> = smatch =
> Same applies to smatch
> make -C /data/data-old/linux-2.6/ M=`pwd`  modules C=1 CHECK=smatch
> make: Entering directory `/data/data-old/linux-2.6'
>   CHECK   /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:535 tpm_stm_i2c_recv() warn: variable dereferenced before check 'chip' (see line 531)
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:748 tpm_st33_i2c_probe() warn: variable dereferenced before check 'platform_data' (see line 659)
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:848 tpm_st33_i2c_pm_resume() warn: should this be a bitwise op?
> /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.c:848 tpm_st33_i2c_pm_resume() warn: should this be a bitwise op?
>   CC [M]  /data/data-old/linux-2.6/drivers/char/tpm/tpm_stm_st33_i2c.o
> 
> Please fix these if applicable - otherwise you'll probably get a friendly reminder to do so by fengguang's build test ;)
> 
> = checkpatch =
> Also please run .../scripts/checkpatch.pl -strict before submission - not everything that is reported might be applicable, but quite often it is.
> 
> 
> 
> Looking forward to your v2 so I can give a more detailed code review of your code.
> 
> 
> Thanks,
> Peter
> 
> 

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