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	Backport upstream solution for working around SPI controller maximum message sizes. Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
		
			
				
	
	
		
			55 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			55 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From 26f9bcad29a6c240881bd4efc90f16a9990dd6c2 Mon Sep 17 00:00:00 2001
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| From: Michal Suchanek <hramrach@gmail.com>
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| Date: Thu, 5 May 2016 17:31:55 -0700
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| Subject: [PATCH 09/10] mtd: spi-nor: add read loop
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| 
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| mtdblock and ubi do not handle the situation when read returns less data
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| than requested. Loop in spi-nor until buffer is filled or an error is
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| returned.
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| 
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| Signed-off-by: Michal Suchanek <hramrach@gmail.com>
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| Signed-off-by: Brian Norris <computersforpeace@gmail.com>
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| Tested-by Cyrille Pitchen <cyrille.pitchen@atmel.com>
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| Acked-by: Michal Suchanek <hramrach@gmail.com>
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| Tested-by: Michal Suchanek <hramrach@gmail.com>
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| ---
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|  drivers/mtd/spi-nor/spi-nor.c | 25 +++++++++++++++++++------
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|  1 file changed, 19 insertions(+), 6 deletions(-)
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| 
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| --- a/drivers/mtd/spi-nor/spi-nor.c
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| +++ b/drivers/mtd/spi-nor/spi-nor.c
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| @@ -890,14 +890,27 @@ static int spi_nor_read(struct mtd_info
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|  	if (ret)
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|  		return ret;
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|  
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| -	ret = nor->read(nor, from, len, buf);
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| +	while (len) {
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| +		ret = nor->read(nor, from, len, buf);
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| +		if (ret == 0) {
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| +			/* We shouldn't see 0-length reads */
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| +			ret = -EIO;
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| +			goto read_err;
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| +		}
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| +		if (ret < 0)
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| +			goto read_err;
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|  
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| -	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
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| -	if (ret < 0)
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| -		return ret;
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| +		WARN_ON(ret > len);
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| +		*retlen += ret;
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| +		buf += ret;
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| +		from += ret;
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| +		len -= ret;
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| +	}
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| +	ret = 0;
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|  
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| -	*retlen += ret;
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| -	return 0;
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| +read_err:
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| +	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
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| +	return ret;
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|  }
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|  
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|  static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
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