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From: Huang Shijie <shijie8@gmail.com>
To: Brian Norris <computersforpeace@gmail.com>
Cc: Boris BREZILLON <boris.brezillon@free-electrons.com>,
	Huang Shijie <shijie.huang@intel.com>,
	Mike Voytovich <mvoytovich@paypal.com>,
	linux-kernel@vger.kernel.org, Huang Shijie <b32955@freescale.com>,
	linux-mtd@lists.infradead.org, Roy Lee <roylee@paypal.com>,
	David Woodhouse <dwmw2@infradead.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] mtd: nand: gpmi: add proper raw access support
Date: Mon, 15 Sep 2014 22:43:02 +0800	[thread overview]
Message-ID: <20140915144259.GA1947@localhost.localdomain> (raw)
In-Reply-To: <20140913173841.GA18093@brian-ubuntu>

On Sat, Sep 13, 2014 at 10:38:41AM -0700, Brian Norris wrote:
> On Sat, Sep 13, 2014 at 11:36:24PM +0800, Huang Shijie wrote:
> > On Fri, Sep 12, 2014 at 02:30:50PM +0200, Boris BREZILLON wrote:
> > > This test validates what's returned by ecc_strength file in sysfs
> > > (which in turn is specified by the NAND controller when initializing
> > > the NAND chip).
> > > 
> > > Doing this should not imply knowing the ECC algorithm in use in the
> > > NAND controller or the layout used to store data on NAND.
> > the difficulty is that the ECC parity area can be not byte aligned.
> 
> Is there a problem with just rounding up to the nearest byte alignment
> and ignoring the few bits that are wasted?

I feel a little confused with the two hooks.

does the ecc->write_page_raw need to write the ECC parity data?

The page's layout after an ecc->write_page  will look like this:
                                              (Block Mark)
                                                    |      |
                                                    |  D   |
                                                    |<---->|
                                                    V      V
     +---+----------+-+----------+-+----------+-+----------+-+
     | M |   data   |E|   data   |E|   data   |E|   data   |E|
     +---+----------+-+----------+-+----------+-+----------+-+

What will the page's layout look like after the ecc->write_page_raw?


thanks
Huang Shijie


WARNING: multiple messages have this Message-ID (diff)
From: Huang Shijie <shijie8@gmail.com>
To: Brian Norris <computersforpeace@gmail.com>
Cc: Boris BREZILLON <boris.brezillon@free-electrons.com>,
	Mike Voytovich <mvoytovich@paypal.com>,
	linux-kernel@vger.kernel.org, Huang Shijie <b32955@freescale.com>,
	linux-mtd@lists.infradead.org, Roy Lee <roylee@paypal.com>,
	Huang Shijie <shijie.huang@intel.com>,
	David Woodhouse <dwmw2@infradead.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] mtd: nand: gpmi: add proper raw access support
Date: Mon, 15 Sep 2014 22:43:02 +0800	[thread overview]
Message-ID: <20140915144259.GA1947@localhost.localdomain> (raw)
In-Reply-To: <20140913173841.GA18093@brian-ubuntu>

On Sat, Sep 13, 2014 at 10:38:41AM -0700, Brian Norris wrote:
> On Sat, Sep 13, 2014 at 11:36:24PM +0800, Huang Shijie wrote:
> > On Fri, Sep 12, 2014 at 02:30:50PM +0200, Boris BREZILLON wrote:
> > > This test validates what's returned by ecc_strength file in sysfs
> > > (which in turn is specified by the NAND controller when initializing
> > > the NAND chip).
> > > 
> > > Doing this should not imply knowing the ECC algorithm in use in the
> > > NAND controller or the layout used to store data on NAND.
> > the difficulty is that the ECC parity area can be not byte aligned.
> 
> Is there a problem with just rounding up to the nearest byte alignment
> and ignoring the few bits that are wasted?

I feel a little confused with the two hooks.

does the ecc->write_page_raw need to write the ECC parity data?

The page's layout after an ecc->write_page  will look like this:
                                              (Block Mark)
                                                    |      |
                                                    |  D   |
                                                    |<---->|
                                                    V      V
     +---+----------+-+----------+-+----------+-+----------+-+
     | M |   data   |E|   data   |E|   data   |E|   data   |E|
     +---+----------+-+----------+-+----------+-+----------+-+

What will the page's layout look like after the ecc->write_page_raw?


thanks
Huang Shijie

WARNING: multiple messages have this Message-ID (diff)
From: shijie8@gmail.com (Huang Shijie)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] mtd: nand: gpmi: add proper raw access support
Date: Mon, 15 Sep 2014 22:43:02 +0800	[thread overview]
Message-ID: <20140915144259.GA1947@localhost.localdomain> (raw)
In-Reply-To: <20140913173841.GA18093@brian-ubuntu>

On Sat, Sep 13, 2014 at 10:38:41AM -0700, Brian Norris wrote:
> On Sat, Sep 13, 2014 at 11:36:24PM +0800, Huang Shijie wrote:
> > On Fri, Sep 12, 2014 at 02:30:50PM +0200, Boris BREZILLON wrote:
> > > This test validates what's returned by ecc_strength file in sysfs
> > > (which in turn is specified by the NAND controller when initializing
> > > the NAND chip).
> > > 
> > > Doing this should not imply knowing the ECC algorithm in use in the
> > > NAND controller or the layout used to store data on NAND.
> > the difficulty is that the ECC parity area can be not byte aligned.
> 
> Is there a problem with just rounding up to the nearest byte alignment
> and ignoring the few bits that are wasted?

I feel a little confused with the two hooks.

does the ecc->write_page_raw need to write the ECC parity data?

The page's layout after an ecc->write_page  will look like this:
                                              (Block Mark)
                                                    |      |
                                                    |  D   |
                                                    |<---->|
                                                    V      V
     +---+----------+-+----------+-+----------+-+----------+-+
     | M |   data   |E|   data   |E|   data   |E|   data   |E|
     +---+----------+-+----------+-+----------+-+----------+-+

What will the page's layout look like after the ecc->write_page_raw?


thanks
Huang Shijie

  parent reply	other threads:[~2014-09-15 14:43 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-10  8:55 [PATCH] mtd: nand: gpmi: add proper raw access support Boris BREZILLON
2014-09-10  8:55 ` Boris BREZILLON
2014-09-10  8:55 ` Boris BREZILLON
2014-09-11 12:09 ` Huang Shijie
2014-09-11 12:09   ` Huang Shijie
2014-09-11 12:09   ` Huang Shijie
2014-09-11 12:36   ` Boris BREZILLON
2014-09-11 12:36     ` Boris BREZILLON
2014-09-11 12:36     ` Boris BREZILLON
2014-09-11 14:25     ` Huang Shijie
2014-09-11 14:25       ` Huang Shijie
2014-09-11 14:25       ` Huang Shijie
2014-09-11 14:38       ` Boris BREZILLON
2014-09-11 14:38         ` Boris BREZILLON
2014-09-11 14:38         ` Boris BREZILLON
2014-09-12  0:45         ` Huang Shijie
2014-09-12  0:45           ` Huang Shijie
2014-09-12  0:45           ` Huang Shijie
2014-09-12 12:30           ` Boris BREZILLON
2014-09-12 12:30             ` Boris BREZILLON
2014-09-12 12:30             ` Boris BREZILLON
2014-09-13 15:36             ` Huang Shijie
2014-09-13 15:36               ` Huang Shijie
2014-09-13 15:36               ` Huang Shijie
2014-09-13 17:38               ` Brian Norris
2014-09-13 17:38                 ` Brian Norris
2014-09-13 17:38                 ` Brian Norris
2014-09-14 14:07                 ` Boris BREZILLON
2014-09-14 14:07                   ` Boris BREZILLON
2014-09-14 14:07                   ` Boris BREZILLON
2014-09-15 14:43                 ` Huang Shijie [this message]
2014-09-15 14:43                   ` Huang Shijie
2014-09-15 14:43                   ` Huang Shijie
2014-09-15 20:12                   ` Boris BREZILLON
2014-09-15 20:12                     ` Boris BREZILLON
2014-09-15 20:12                     ` Boris BREZILLON
2014-09-17 15:26                     ` Huang Shijie
2014-09-17 15:26                       ` Huang Shijie
2014-09-17 15:26                       ` Huang Shijie
2014-09-17 18:16                       ` Boris BREZILLON
2014-09-17 18:16                         ` Boris BREZILLON
2014-09-17 18:16                         ` Boris BREZILLON
2014-09-29  1:22     ` Iwo Mergler
2014-09-29  1:22       ` Iwo Mergler
2014-09-29  1:22       ` Iwo Mergler
2014-09-30  8:04       ` Boris Brezillon
2014-09-30  8:04         ` Boris Brezillon
2014-09-30  8:04         ` Boris Brezillon
2014-10-02  6:52         ` Iwo Mergler
2014-10-02  6:52           ` Iwo Mergler
2014-10-02  6:52           ` Iwo Mergler
2014-09-11 14:29 ` Huang Shijie
2014-09-11 14:29   ` Huang Shijie
2014-09-11 14:29   ` Huang Shijie
2014-09-11 14:45   ` Boris BREZILLON
2014-09-11 14:45     ` Boris BREZILLON
2014-09-11 14:45     ` Boris BREZILLON
2014-09-12  0:40     ` Huang Shijie
2014-09-12  0:40       ` Huang Shijie
2014-09-12  0:40       ` Huang Shijie

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