linux-kernel - Re: [PATCH] mtd: cfi_cmdset_0002: dynamically determine the max sectors

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Date:   Fri, 14 Jun 2019 13:09:32 +0530
From:   Vignesh Raghavendra <vigneshr@...com>
To:     Chris Packham <Chris.Packham@...iedtelesis.co.nz>,
        "dwmw2@...radead.org" <dwmw2@...radead.org>,
        "computersforpeace@...il.com" <computersforpeace@...il.com>,
        "marek.vasut@...il.com" <marek.vasut@...il.com>,
        "miquel.raynal@...tlin.com" <miquel.raynal@...tlin.com>,
        "richard@....at" <richard@....at>
CC:     "sr@...x.de" <sr@...x.de>,
        "linux-mtd@...ts.infradead.org" <linux-mtd@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mtd: cfi_cmdset_0002: dynamically determine the max
 sectors



On 14/06/19 8:53 AM, Chris Packham wrote:
> Hi All,
> 
> I think this may have got lost in the change of maintainer for mtd.
> 

I do have this in my queue of patches for mtd/next and will forward to
Miquel once he is back.


> On 22/05/19 12:06 PM, Chris Packham wrote:
>> Because PPB unlocking unlocks the whole chip cfi_ppb_unlock() needs to
>> remember the locked status for each sector so it can re-lock the
>> unaddressed sectors. Dynamically calculate the maximum number of sectors
>> rather than using a hardcoded value that is too small for larger chips.
>>
>> Tested with Spansion S29GL01GS11TFI flash device.
>>
>> Signed-off-by: Chris Packham <chris.packham@...iedtelesis.co.nz>

Acked-by: Vignesh Raghavendra <vigneshr@...com>

Regards
Vignesh

>> ---
>>   drivers/mtd/chips/cfi_cmdset_0002.c | 13 ++++++++-----
>>   1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
>> index c8fa5906bdf9..a1a7d334aa82 100644
>> --- a/drivers/mtd/chips/cfi_cmdset_0002.c
>> +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
>> @@ -2533,8 +2533,6 @@ struct ppb_lock {
>>   	int locked;
>>   };
>>   
>> -#define MAX_SECTORS			512
>> -
>>   #define DO_XXLOCK_ONEBLOCK_LOCK		((void *)1)
>>   #define DO_XXLOCK_ONEBLOCK_UNLOCK	((void *)2)
>>   #define DO_XXLOCK_ONEBLOCK_GETLOCK	((void *)3)
>> @@ -2633,6 +2631,7 @@ static int __maybe_unused cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs,
>>   	int i;
>>   	int sectors;
>>   	int ret;
>> +	int max_sectors;
>>   
>>   	/*
>>   	 * PPB unlocking always unlocks all sectors of the flash chip.
>> @@ -2640,7 +2639,11 @@ static int __maybe_unused cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs,
>>   	 * first check the locking status of all sectors and save
>>   	 * it for future use.
>>   	 */
>> -	sect = kcalloc(MAX_SECTORS, sizeof(struct ppb_lock), GFP_KERNEL);
>> +	max_sectors = 0;
>> +	for (i = 0; i < mtd->numeraseregions; i++)
>> +		max_sectors += regions[i].numblocks;
>> +
>> +	sect = kcalloc(max_sectors, sizeof(struct ppb_lock), GFP_KERNEL);
>>   	if (!sect)
>>   		return -ENOMEM;
>>   
>> @@ -2689,9 +2692,9 @@ static int __maybe_unused cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs,
>>   		}
>>   
>>   		sectors++;
>> -		if (sectors >= MAX_SECTORS) {
>> +		if (sectors >= max_sectors) {
>>   			printk(KERN_ERR "Only %d sectors for PPB locking supported!\n",
>> -			       MAX_SECTORS);
>> +			       max_sectors);
>>   			kfree(sect);
>>   			return -EINVAL;
>>   		}
>>
> 

-- 
Regards
Vignesh