linux-kernel - Re: [RESEND PATCH v2 2/3] mtd: spi-nor: parse SFDP Sector Map Parameter Table

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Date:   Fri, 7 Sep 2018 12:10:30 +0300
From:   Tudor Ambarus <tudor.ambarus@...rochip.com>
To:     Marek Vasut <marek.vasut@...il.com>,
        <cyrille.pitchen@...rochip.com>, <dwmw2@...radead.org>,
        <computersforpeace@...il.com>, <boris.brezillon@...tlin.com>,
        <richard@....at>
CC:     <linux-mtd@...ts.infradead.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <nicolas.ferre@...rochip.com>,
        <Cristian.Birsan@...rochip.com>
Subject: Re: [RESEND PATCH v2 2/3] mtd: spi-nor: parse SFDP Sector Map
 Parameter Table



On 09/03/2018 08:40 PM, Marek Vasut wrote:
> On 08/27/2018 12:26 PM, Tudor Ambarus wrote:
> [...]
>> +static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt)
>> +{
>> +	const u32 *ret = NULL;
>> +	u32 i, addr;
>> +	int err;
>> +	u8 addr_width, read_opcode, read_dummy;
>> +	u8 read_data_mask, data_byte, map_id;
>> +
>> +	addr_width = nor->addr_width;
>> +	read_dummy = nor->read_dummy;
>> +	read_opcode = nor->read_opcode;
>> +
>> +	map_id = 0;
>> +	i = 0;
>> +	/* Determine if there are any optional Detection Command Descriptors */
>> +	while (!(smpt[i] & SMPT_DESC_TYPE_MAP)) {
>> +		read_data_mask = SMPT_CMD_READ_DATA(smpt[i]);
>> +		nor->addr_width = spi_nor_smpt_addr_width(nor, smpt[i]);
>> +		nor->read_dummy = spi_nor_smpt_read_dummy(nor, smpt[i]);
>> +		nor->read_opcode = SMPT_CMD_OPCODE(smpt[i]);
>> +		addr = smpt[i + 1];
>> +
>> +		err = spi_nor_read_raw(nor, addr, 1, &data_byte);
>> +		if (err)
>> +			goto out;
>> +
>> +		/*
>> +		 * Build an index value that is used to select the Sector Map
>> +		 * Configuration that is currently in use.
>> +		 */
>> +		map_id = map_id << 1 | (!(data_byte & read_data_mask) ? 0 : 1);
> 
> You can drop the ternary operator part completely ^

I'll use !! instead.

> 
>> +		i = i + 2;
>> +	}
>> +
>> +	/* Find the matching configuration map */
>> +	while (SMPT_MAP_ID(smpt[i]) != map_id) {
>> +		if (smpt[i] & SMPT_DESC_END)
>> +			goto out;
>> +		/* increment the table index to the next map */
>> +		i += SMPT_MAP_REGION_COUNT(smpt[i]) + 1;
>> +	}
>> +
>> +	ret = smpt + i;
>> +	/* fall through */
>> +out:
>> +	nor->addr_width = addr_width;
>> +	nor->read_dummy = read_dummy;
>> +	nor->read_opcode = read_opcode;
>> +	return ret;
>> +}
>> +
>> +static void
>> +spi_nor_region_check_overlay(struct spi_nor_erase_region *region,
>> +			     const struct spi_nor_erase_type *erase,
>> +			     const u8 erase_type)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < SNOR_ERASE_TYPE_MAX; i++) {
>> +		if (!(erase_type & BIT(i)))
>> +			continue;
>> +		if (region->size & erase[i].size_mask) {
>> +			spi_nor_region_mark_overlay(region);
>> +			return;
>> +		}
>> +	}
>> +}
>> +
>> +static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
>> +					      const u32 *smpt)
>> +{
>> +	struct spi_nor_erase_map *map = &nor->erase_map;
>> +	const struct spi_nor_erase_type *erase = map->erase_type;
>> +	struct spi_nor_erase_region *region;
>> +	u64 offset;
>> +	u32 region_count;
>> +	int i, j;
>> +	u8 erase_type;
>> +
>> +	region_count = SMPT_MAP_REGION_COUNT(*smpt);
>> +	region = devm_kcalloc(nor->dev, region_count, sizeof(*region),
>> +			      GFP_KERNEL);
> 
> Is this memory always correctly free'd ?

Yes. It will be free'd when the driver detaches from the device.

Thanks,
ta