[PATCH v6, 5/8] mtd: m25p80: Let m25p80_read() fallback to spi transfer

Cyrille Pitchen cyrille.pitchen at atmel.com
Mon Oct 10 01:29:49 PDT 2016


Hi all,


Le 10/10/2016 à 10:04, Florian Fainelli a écrit :
> On 08/24/2016 03:04 PM, Kamal Dasu wrote:
>> In m25p80_read() even though spi_flash_read() is supported
>> by some drivers, under certain circumstances like unaligned
>> buffer, address or address range limitations on certain SoCs
>> let it fallback to core spi reads. Such drivers are expected
>> to return -EAGAIN so that the m25p80_read() uses standard
>> spi transfer.
>>
>> Signed-off-by: Kamal Dasu <kdasu.kdev at gmail.com>
> 
> MTD folks, any comments on this?
> 
>> ---
>>  drivers/mtd/devices/m25p80.c | 11 +++++++++--
>>  1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
>> index 9cf7fcd..77c2d2c 100644
>> --- a/drivers/mtd/devices/m25p80.c
>> +++ b/drivers/mtd/devices/m25p80.c
>> @@ -155,9 +155,16 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
>>  		msg.data_nbits = m25p80_rx_nbits(nor);
>>  
>>  		ret = spi_flash_read(spi, &msg);
>> -		if (ret < 0)
>> +
>> +		if (ret >= 0)
>> +			return msg.retlen;
>> +
>> +		/*
>> +		 * some spi master drivers might need to fallback to
>> +		 * normal spi transfer
>> +		 */
>> +		if (ret != -EAGAIN)
I just wonder whether EINVAL would be a better choice.
>>  			return ret;
>> -		return msg.retlen;
>>  	}
>>  
>>  	spi_message_init(&m);
>>
> 

Best regards,

Cyrille



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