From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Stefan Agner <stefan@agner.ch>
Cc: bbrezillon@kernel.org, richard@nod.at,
Sascha Hauer <s.hauer@pengutronix.de>,
linux-kernel@vger.kernel.org, marek.vasut@gmail.com,
Boris Brezillon <boris.brezillon@collabora.com>,
linux-mtd@lists.infradead.org, computersforpeace@gmail.com,
dwmw2@infradead.org
Subject: Re: [PATCH] mtd: rawnand: use longest matching pattern
Date: Mon, 20 May 2019 16:31:31 +0200 [thread overview]
Message-ID: <20190520163131.7c143ebe@xps13> (raw)
In-Reply-To: <20190419074717.22576-1-stefan@agner.ch>
Hi Stefan,
Stefan Agner <stefan@agner.ch> wrote on Fri, 19 Apr 2019 09:47:17 +0200:
> Sometimes the exec_op parser does not choose the optimal pattern if
> multiple patterns with optional elements are available. Since the stack
> automatically splits operations in multiple exec_op calls, a non-optimal
> pattern gets broken up into multiple calls. E.g. an OOB read using the
> vf610 driver:
> nand: executing subop:
> nand: ->CMD [0x00]
> nand: ->ADDR [5 cyc: 00 08 ea 94 02]
> nand: ->CMD [0x30]
> nand: ->WAITRDY [max 200000 ms]
> nand: DATA_IN [64 B]
> nand: executing subop:
> nand: CMD [0x00]
> nand: ADDR [5 cyc: 00 08 ea 94 02]
> nand: CMD [0x30]
> nand: WAITRDY [max 200000 ms]
> nand: ->DATA_IN [64 B]
>
> However, the vf610 driver has a pattern which can execute the complete
> command in a single go...
>
> This patch makes sure that the longest matching pattern is chosen
> instead of the first (potentially only partial) match. With this
> change the vf610 reads the OOB in a single exec_op call:
> nand: executing subop:
> nand: ->CMD [0x00]
> nand: ->ADDR [5 cyc: 00 08 c0 1d 00]
> nand: ->CMD [0x30]
> nand: ->WAITRDY [max 200000 ms]
> nand: ->DATA_IN [64 B]
>
> Reported-by: Sascha Hauer <s.hauer@pengutronix.de>
> Suggested-by: Boris Brezillon <boris.brezillon@collabora.com>
> Tested-by: Stefan Agner <stefan@agner.ch>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
Applied, thanks.
Miquèl
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WARNING: multiple messages have this Message-ID (diff)
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Stefan Agner <stefan@agner.ch>
Cc: bbrezillon@kernel.org, richard@nod.at, dwmw2@infradead.org,
computersforpeace@gmail.com, marek.vasut@gmail.com,
linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
Sascha Hauer <s.hauer@pengutronix.de>,
Boris Brezillon <boris.brezillon@collabora.com>
Subject: Re: [PATCH] mtd: rawnand: use longest matching pattern
Date: Mon, 20 May 2019 16:31:31 +0200 [thread overview]
Message-ID: <20190520163131.7c143ebe@xps13> (raw)
In-Reply-To: <20190419074717.22576-1-stefan@agner.ch>
Hi Stefan,
Stefan Agner <stefan@agner.ch> wrote on Fri, 19 Apr 2019 09:47:17 +0200:
> Sometimes the exec_op parser does not choose the optimal pattern if
> multiple patterns with optional elements are available. Since the stack
> automatically splits operations in multiple exec_op calls, a non-optimal
> pattern gets broken up into multiple calls. E.g. an OOB read using the
> vf610 driver:
> nand: executing subop:
> nand: ->CMD [0x00]
> nand: ->ADDR [5 cyc: 00 08 ea 94 02]
> nand: ->CMD [0x30]
> nand: ->WAITRDY [max 200000 ms]
> nand: DATA_IN [64 B]
> nand: executing subop:
> nand: CMD [0x00]
> nand: ADDR [5 cyc: 00 08 ea 94 02]
> nand: CMD [0x30]
> nand: WAITRDY [max 200000 ms]
> nand: ->DATA_IN [64 B]
>
> However, the vf610 driver has a pattern which can execute the complete
> command in a single go...
>
> This patch makes sure that the longest matching pattern is chosen
> instead of the first (potentially only partial) match. With this
> change the vf610 reads the OOB in a single exec_op call:
> nand: executing subop:
> nand: ->CMD [0x00]
> nand: ->ADDR [5 cyc: 00 08 c0 1d 00]
> nand: ->CMD [0x30]
> nand: ->WAITRDY [max 200000 ms]
> nand: ->DATA_IN [64 B]
>
> Reported-by: Sascha Hauer <s.hauer@pengutronix.de>
> Suggested-by: Boris Brezillon <boris.brezillon@collabora.com>
> Tested-by: Stefan Agner <stefan@agner.ch>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
Applied, thanks.
Miquèl
next prev parent reply other threads:[~2019-05-20 14:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-19 7:47 [PATCH] mtd: rawnand: use longest matching pattern Stefan Agner
2019-04-19 7:47 ` Stefan Agner
2019-05-20 14:31 ` Miquel Raynal [this message]
2019-05-20 14:31 ` Miquel Raynal
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