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From: Ryan Mallon <ryan@bluewatersys.com>
To: Baruch Siach <baruch@tkos.co.il>
Cc: linux-mtd@lists.infradead.org,
	David Woodhouse <dwmw2@infradead.org>,
	linux kernel <linux-kernel@vger.kernel.org>,
	mike@steroidmicros.com, spi-devel-general@lists.sourceforge.net
Subject: Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver
Date: Mon, 22 Jun 2009 16:25:36 +1200	[thread overview]
Message-ID: <4A3F07C0.9030001@bluewatersys.com> (raw)
In-Reply-To: <20090622041457.GC6027@tarshish>

Baruch Siach wrote:
> Hi Ryan,
> 
> On Mon, Jun 22, 2009 at 03:58:51PM +1200, Ryan Mallon wrote:
>> +static int sst25l_erase_block(struct sst25l_flash *flash, u32 offset)
>> +{
>> +	u8 command[4];
>> +	int err;
>> +
>> +	err = sst25l_write_enable(flash, 1);
> 
> Is this enable/disable strictly required for each write/erase? Can't we just 
> enable write once?

The datasheet says that prior to any write/erase instruction the write
enable instruction must be sent.

~Ryan

-- 
Bluewater Systems Ltd - ARM Technology Solution Centre

       Ryan Mallon                              Unit 5, Amuri Park
       Phone: +64 3 3779127                     404 Barbadoes St
       Fax:   +64 3 3779135                     PO Box 13 889
       Email: ryan@bluewatersys.com             Christchurch, 8013
       Web:   http://www.bluewatersys.com       New Zealand
       Freecall Australia  1800 148 751         USA 1800 261 2934

WARNING: multiple messages have this Message-ID (diff)
From: Ryan Mallon <ryan@bluewatersys.com>
To: Baruch Siach <baruch@tkos.co.il>
Cc: David Woodhouse <dwmw2@infradead.org>,
	linux-mtd@lists.infradead.org,
	spi-devel-general@lists.sourceforge.net, mike@steroidmicros.com,
	linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver
Date: Mon, 22 Jun 2009 16:25:36 +1200	[thread overview]
Message-ID: <4A3F07C0.9030001@bluewatersys.com> (raw)
In-Reply-To: <20090622041457.GC6027@tarshish>

Baruch Siach wrote:
> Hi Ryan,
> 
> On Mon, Jun 22, 2009 at 03:58:51PM +1200, Ryan Mallon wrote:
>> +static int sst25l_erase_block(struct sst25l_flash *flash, u32 offset)
>> +{
>> +	u8 command[4];
>> +	int err;
>> +
>> +	err = sst25l_write_enable(flash, 1);
> 
> Is this enable/disable strictly required for each write/erase? Can't we just 
> enable write once?

The datasheet says that prior to any write/erase instruction the write
enable instruction must be sent.

~Ryan

-- 
Bluewater Systems Ltd - ARM Technology Solution Centre

       Ryan Mallon                              Unit 5, Amuri Park
       Phone: +64 3 3779127                     404 Barbadoes St
       Fax:   +64 3 3779135                     PO Box 13 889
       Email: ryan@bluewatersys.com             Christchurch, 8013
       Web:   http://www.bluewatersys.com       New Zealand
       Freecall Australia  1800 148 751         USA 1800 261 2934

  reply	other threads:[~2009-06-22  4:23 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-22  3:58 [PATCH] SST25L (non JEDEC) SPI Flash driver Ryan Mallon
2009-06-22  4:14 ` [spi-devel-general] " Baruch Siach
2009-06-22  4:14   ` Baruch Siach
2009-06-22  4:25   ` Ryan Mallon [this message]
2009-06-22  4:25     ` Ryan Mallon
2009-06-22  8:15 ` Artem Bityutskiy
2009-06-22  8:15   ` Artem Bityutskiy
2009-06-22  8:22 ` Linus Walleij
2009-06-22  8:22   ` Linus Walleij
2009-06-22 21:56   ` Ryan Mallon
2009-06-22 21:56     ` Ryan Mallon
2009-06-23  7:04     ` Linus Walleij
2009-06-23  7:04       ` Linus Walleij
2009-06-23 20:48       ` Ryan Mallon
2009-06-23 20:48         ` Ryan Mallon
2009-06-24 22:43         ` Linus Walleij
2009-06-24 22:43           ` Linus Walleij
2009-06-24 22:49           ` Ryan Mallon
2009-06-24 22:49             ` Ryan Mallon
2009-06-24 23:49             ` Linus Walleij
2009-06-24 23:49               ` Linus Walleij
2009-06-25  1:39 ` [spi-devel-general] " H Hartley Sweeten
2009-06-25  1:39   ` H Hartley Sweeten
2009-06-25  2:06   ` Ryan Mallon
2009-06-25  2:06     ` Ryan Mallon
2009-06-25  2:30     ` H Hartley Sweeten
2009-06-25  2:30       ` H Hartley Sweeten
2009-06-25  2:52       ` Ryan Mallon
2009-06-25  2:52         ` Ryan Mallon
2009-06-25  7:49     ` Linus Walleij
2009-06-25  7:49       ` Linus Walleij
2009-06-25  7:49       ` Linus Walleij
  -- strict thread matches above, loose matches on Subject: below --
2009-06-24 23:59 Ryan Mallon
2009-06-25  0:08 ` Linus Walleij
2009-07-03  0:50   ` [spi-devel-general] " David Brownell

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