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

From: Vignesh Raghavendra
Date: Fri Jun 14 2019 - 03:44:20 EST




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@xxxxxxxxxxxxxxxxxxx>

Acked-by: Vignesh Raghavendra <vigneshr@xxxxxx>

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