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

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Message-ID: <8e80d911f0dd4759b3edc72fb76530d6@svr-chch-ex1.atlnz.lc>
Date:   Fri, 14 Jun 2019 03:23:57 +0000
From:   Chris Packham <Chris.Packham@...iedtelesis.co.nz>
To:     "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>,
        "vigneshr@...com" <vigneshr@...com>,
        "miquel.raynal@...tlin.com" <miquel.raynal@...tlin.com>
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

Hi All,

I think this may have got lost in the change of maintainer for mtd.

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>
> ---
>   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;
>   		}
>