linux-kernel - RE: [PATCH] sst25l.c: simplify reading the device ManID/DevID

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <1272564466.2593.3.camel@localhost.localdomain>
Date:	Thu, 29 Apr 2010 21:07:46 +0300
From:	Artem Bityutskiy <dedekind1@...il.com>
To:	H Hartley Sweeten <hartleys@...ionengravers.com>
Cc:	David Woodhouse <dwmw2@...radead.org>,
	"ryan@...ewatersys.com" <ryan@...ewatersys.com>,
	"andre@...ewatersys.com" <andre@...ewatersys.com>,
	"linux-mtd@...ts.infradead.org" <linux-mtd@...ts.infradead.org>,
	Linux Kernel <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] sst25l.c: simplify reading the device ManID/DevID

On Thu, 2010-04-29 at 12:11 -0500, H Hartley Sweeten wrote:
> On Wednesday, April 28, 2010 10:37 PM, Artem Bityutskiy wrote:
> > On Tue, 2010-04-20 at 18:17 -0500, H Hartley Sweeten wrote:
> >> The Read-ID command will continuously output the Manufacture ID and Device ID
> >> until the command is terminated by a low to high transition on the CE# pin.
> >> We can take advantage of this in the sst25l_match_device routine by reading
> >> both bytes in one spi_write_then_read transaction.
> >> 
> >> Signed-off-by: H Hartley Sweeten <hsweeten@...ionengravers.com>
> >> Cc: David Woodhouse <dwmw2@...radead.org>
> >> Cc: Andre Renaud <andre@...ewatersys.com>
> >> Cc: Ryan Mallon <ryan@...ewatersys.com>
> >
> > Pushed to l2-mtd-2.6.git / dunno.
> 
> Artem,
> 
> I have discovered that the Read-Status-Register command has the same problem.
> With the SST25L SPI flash chips, if the chip enable is deasserted after sending
> a command that command will get aborted.
> 
> I ran across this while testing a new spi master driver for the ep93xx on an
> EDB9307A dev board.  That board uses the processors SFRMOUT signal as part of
> the chip select logic.  Unfortunately the ep93xx only asserts the SFRMOUT
> signal as long as the spi transmit fifo contains data.  As soon as the last
> bit is clocked into the receive fifo it gets deasserted.  Many of the other
> ep93xx based boards have that same issue.
> 
> I have an updated patch that changes both of these into one synchronous message
> which fixes the sst25l_status and sst25l_match_device functions.  These changes
> should be transparent to any users of this driver.
> 
> Could you drop the current patch and I will submit the updated one for review?

Of course, just send it.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/