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Subject: Re: [PATCH] mtd: nand: Fix build error while
 CONFIG_MTD_NAND_ECC_SW_BCH is set to module
To:     Boris Brezillon <boris.brezillon@collabora.com>
References: <20190410130747.35692-1-yuehaibing@huawei.com>
 <20190410153920.68267a1a@collabora.com>
 <20190410155856.655122c8@collabora.com>
 <8b020124-4008-6081-c04c-eaefb7875878@huawei.com>
 <20190410162927.17ea678b@collabora.com>
 <41165c39-da0c-0f15-87f9-4fb588b77dcc@huawei.com>
 <20190410181843.489a4e33@xps13> <20190410190328.433a954f@collabora.com>
 <79bce66d-6bb5-39f9-6f36-0667dede52fd@huawei.com>
 <20190412170450.4d215ad4@collabora.com>
CC:     Miquel Raynal <miquel.raynal@bootlin.com>, <richard@nod.at>,
        <computersforpeace@gmail.com>, <marek.vasut@gmail.com>,
        <paul.burton@mips.com>, <bbrezillon@kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-mtd@lists.infradead.org>
From:   YueHaibing <yuehaibing@huawei.com>
Message-ID: <eae187bf-3b84-bbc9-4dee-7bbc2cee641c@huawei.com>
Date:   Fri, 12 Apr 2019 23:23:08 +0800
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On 2019/4/12 23:04, Boris Brezillon wrote:
> On Fri, 12 Apr 2019 22:28:57 +0800
> YueHaibing <yuehaibing@huawei.com> wrote:
> 
>> On 2019/4/11 1:03, Boris Brezillon wrote:
>>> On Wed, 10 Apr 2019 18:18:43 +0200
>>> Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>>>   
>>>> Hi YueHaibing,
>>>>
>>>> YueHaibing <yuehaibing@huawei.com> wrote on Wed, 10 Apr 2019 23:03:24
>>>> +0800:
>>>>  
>>>>> On 2019/4/10 22:29, Boris Brezillon wrote:    
>>>>>> On Wed, 10 Apr 2019 22:22:16 +0800
>>>>>> YueHaibing <yuehaibing@huawei.com> wrote:
>>>>>>       
>>>>>>> On 2019/4/10 21:58, Boris Brezillon wrote:      
>>>>>>>> On Wed, 10 Apr 2019 15:39:28 +0200
>>>>>>>> Boris Brezillon <boris.brezillon@collabora.com> wrote:
>>>>>>>>         
>>>>>>>>> On Wed, 10 Apr 2019 21:07:47 +0800
>>>>>>>>> Yue Haibing <yuehaibing@huawei.com> wrote:
>>>>>>>>>        
>>>>>>>>>> From: YueHaibing <yuehaibing@huawei.com>
>>>>>>>>>>
>>>>>>>>>> Fix gcc build error while CONFIG_MTD_NAND_ECC_SW_BCH
>>>>>>>>>> is set to module:
>>>>>>>>>>
>>>>>>>>>> drivers/mtd/nand/raw/nand_base.o: In function `nand_cleanup':
>>>>>>>>>> (.text+0xef6): undefined reference to `nand_bch_free'
>>>>>>>>>> drivers/mtd/nand/raw/nand_base.o: In function `nand_scan_tail':
>>>>>>>>>> nand_base.c:(.text+0xa101): undefined reference to `nand_bch_calculate_ecc'
>>>>>>>>>> nand_base.c:(.text+0xa120): undefined reference to `nand_bch_correct_data'
>>>>>>>>>> nand_base.c:(.text+0xa269): undefined reference to `nand_bch_init'
>>>>>>>>>>
>>>>>>>>>> CONFIG_MTD_NAND_ECC_SW_BCH should not be set to M,
>>>>>>>>>> because MTD_RAW_NAND need it while linked.
>>>>>>>>>>
>>>>>>>>>> Reported-by: Hulk Robot <hulkci@huawei.com>
>>>>>>>>>> Fixes: 193bd4002644 ("mtd: nand: add software BCH ECC support"          
>>>>>>>>>
>>>>>>>>> Nope, it's not this one that introduced the regression.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>        
>>>>>>>>>> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>>>>>>>>>> ---
>>>>>>>>>>  drivers/mtd/nand/raw/Kconfig | 2 +-
>>>>>>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>>>>>
>>>>>>>>>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>>>>>>>>>> index 615d738..0500c42 100644
>>>>>>>>>> --- a/drivers/mtd/nand/raw/Kconfig
>>>>>>>>>> +++ b/drivers/mtd/nand/raw/Kconfig
>>>>>>>>>> @@ -22,7 +22,7 @@ menuconfig MTD_RAW_NAND
>>>>>>>>>>  if MTD_RAW_NAND
>>>>>>>>>>  
>>>>>>>>>>  config MTD_NAND_ECC_SW_BCH
>>>>>>>>>> -	tristate "Support software BCH ECC"
>>>>>>>>>> +	bool "Support software BCH ECC"
>>>>>>>>>>  	select BCH
>>>>>>>>>>  	default n
>>>>>>>>>>  	help          
>>>>>>>>>
>>>>>>>>> Should be fixed with the following diff squashed into:
>>>>>>>>>
>>>>>>>>> 51ef1d0b2095 ("mtd: nand: Clarify Kconfig entry for software BCH ECC algorithm")
>>>>>>>>>        
>>>>>>>>> --->8---          
>>>>>>>>> diff --git a/include/linux/mtd/nand_bch.h b/include/linux/mtd/nand_bch.h
>>>>>>>>> index b8106651f807..06ce2b655c13 100644
>>>>>>>>> --- a/include/linux/mtd/nand_bch.h
>>>>>>>>> +++ b/include/linux/mtd/nand_bch.h
>>>>>>>>> @@ -15,7 +15,7 @@ struct mtd_info;
>>>>>>>>>  struct nand_chip;
>>>>>>>>>  struct nand_bch_control;
>>>>>>>>>  
>>>>>>>>> -#if defined(CONFIG_MTD_NAND_ECC_BCH)
>>>>>>>>> +#if defined(CONFIG_MTD_NAND_ECC_SW_BCH)
>>>>>>>>>  
>>>>>>>>>  static inline int mtd_nand_has_bch(void) { return 1; }
>>>>>>>>>  
>>>>>>>>> @@ -39,7 +39,7 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd);
>>>>>>>>>   */
>>>>>>>>>  void nand_bch_free(struct nand_bch_control *nbc);
>>>>>>>>>  
>>>>>>>>> -#else /* !CONFIG_MTD_NAND_ECC_BCH */
>>>>>>>>> +#else /* !CONFIG_MTD_NAND_ECC_SW_BCH */
>>>>>>>>>  
>>>>>>>>>  static inline int mtd_nand_has_bch(void) { return 0; }
>>>>>>>>>  
>>>>>>>>> @@ -64,6 +64,6 @@ static inline struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
>>>>>>>>>  
>>>>>>>>>  static inline void nand_bch_free(struct nand_bch_control *nbc) {}
>>>>>>>>>  
>>>>>>>>> -#endif /* CONFIG_MTD_NAND_ECC_BCH */
>>>>>>>>> +#endif /* CONFIG_MTD_NAND_ECC_SW_BCH */
>>>>>>>>>  
>>>>>>>>>  #endif /* __MTD_NAND_BCH_H__ */        
>>>>>>>>
>>>>>>>> Sorry, I didn't look at the right branch, this part of the code was
>>>>>>>> correct, but we still have a problem to express the RAW_NAND(y) ->
>>>>>>>> SW_BCH(y) dependency.        
>>>>>>>
>>>>>>> It seems this dependency is not always need,
>>>>>>>
>>>>>>> case MTD_RAW_NAND set to y works well while CONFIG_MTD_NAND_ECC_SW_BCH is not set.      
>>>>>>
>>>>>> Yes, I know, but forcing nand_bch to a be a boolean is not the right
>>>>>> solution either, hence my suggestion to use 'imply'.      
>>>>
>>>> Why exactly? SW BCH is going to be converted to the generic ECC engine
>>>> abstraction and IIRC you told me that it would not be problematic to
>>>> turn it into a boolean?  
>>>
>>> Yes, I told you we should turn it into a boolean and embed the code in
>>> the nandcore.o object which can itself be linked as a module or embedded
>>> in the kernel image (see above for a version adapted for nand.o). That's
>>> not exactly what Yue proposed.  
>>
>> So is there anothor fix or just to pick my v2 ?
>>
>> https://patchwork.ozlabs.org/patch/1083480/
> 
> 
> Looks like someone posted it already:

Thanks!

> 
> https://patchwork.ozlabs.org/patch/1083603/
> 
> .
>