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From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
To: Brian Norris <computersforpeace@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	Lior Amsalem <alior@marvell.com>,
	Jason Cooper <jason@lakedaemon.net>,
	Tawfik Bayouk <tawfik@marvell.com>,
	Artem Bityutskiy <dedekind1@gmail.com>,
	Daniel Mack <zonque@gmail.com>,
	linux-mtd@lists.infradead.org,
	Gregory Clement <gregory.clement@free-electrons.com>,
	Willy Tarreau <w@1wt.eu>
Subject: Re: [PATCH 01/21] mtd: nand: pxa3xx: Allocate data buffer on detected flash size
Date: Mon, 30 Sep 2013 09:37:57 -0300	[thread overview]
Message-ID: <20130930123756.GB2417@localhost> (raw)
In-Reply-To: <20130926201032.GL23337@ld-irv-0074.broadcom.com>

On Thu, Sep 26, 2013 at 01:10:32PM -0700, Brian Norris wrote:
> On Thu, Sep 19, 2013 at 01:01:25PM -0300, Ezequiel Garcia wrote:
> > This commit replaces the currently hardcoded buffer size, by a
> > dynamic detection scheme. First a small 256 bytes buffer is allocated
> > so the device can be detected (using READID and friends commands).
> > 
> > After detection, this buffer is released and a new buffer is allocated
> > to acommodate the page size plus out-of-band size.
> > 
> > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> 
> This is the patch that breaks Daniel's DMA setup, right? It looks a bit
> off.

What do you mean by 'a bit off'?

> I'll wait to comment on it much until v2.
> 

Ok... let me re-work it then and prepare the v2.

> BTW, there is a similar issue with at least one other driver (denali.c,
> maybe others) where the driver uses some hard assumptions about the
> maximum page/OOB sizes (NAND_MAX_PAGESIZE and NAND_MAX_OOBSIZE). This is
> kind of ugly and not very sustainable/maintainable, since these
> dimensions keep increasing. I appreciate your effort to avoid simply
> kludging in a larger MAX_BUFF_SIZE :) I had similar plans for the other
> drivers, but I don't know if we'll have much testing opportunities for
> the ancient ones...
> 
> Also, it seems like your driver has a few potential leaks right now. If
> alloc_nand_resource() succeeds but pxa3xx_nand_probe() later fails
> (e.g., in pxa3xx_nand_scan()), you don't clean up after yourself. You
> should address this soon, even if not in this patch series.
> 

Hm.. are you sure about that? AFAICS, there's no leak at all.

If alloc_nand_resource() succeeds, the only leakable resources allocated
are the ones allocated at pxa3xx_nand_init_buff() and the NAND base
stuff.

If pxa3xx_nand_probe() later fails to complete, it calls pxa3xx_nand_remove()
in this part:

	if (!probe_success) {
		pxa3xx_nand_remove(pdev);
		return -ENODEV;
	}

Which takes care of cleaning both the buffers and the NAND base stuff.

Or am I missing something?

Feel free to ask more questions and thanks a lot for the feedback.
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com

  reply	other threads:[~2013-09-30 12:38 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-19 16:01 [PATCH 00/21] Armada 370/XP NAND support Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 01/21] mtd: nand: pxa3xx: Allocate data buffer on detected flash size Ezequiel Garcia
2013-09-26 20:10   ` Brian Norris
2013-09-30 12:37     ` Ezequiel Garcia [this message]
2013-10-02 21:14       ` Brian Norris
2013-09-19 16:01 ` [PATCH 02/21] mtd: nand: pxa3xx: Disable OOB on arbitrary length commands Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 03/21] mtd: nand: pxa3xx: Use a completion to signal device ready Ezequiel Garcia
2013-10-02 21:56   ` Brian Norris
2013-10-04 18:54     ` Ezequiel Garcia
2013-10-16 20:23       ` Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 04/21] mtd: nand: pxa3xx: Add bad block handling Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 05/21] mtd: nand: pxa3xx: Add driver-specific ECC BCH support Ezequiel Garcia
2013-10-03  0:24   ` Brian Norris
2013-10-04 19:49     ` Ezequiel Garcia
2013-10-05  0:27       ` Brian Norris
2013-10-17 22:27         ` Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 06/21] mtd: nand: pxa3xx: Configure detected pages-per-block Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 07/21] mtd: nand: pxa3xx: Clear cmd buffer #3 (NDCB3) on command start Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 08/21] mtd: nand: pxa3xx: Make config menu show supported platforms Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 09/21] mtd: nand: pxa3xx: Split FIFO size from to-be-read FIFO count Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 10/21] mtd: nand: pxa3xx: Replace host->page_size by mtd->writesize Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 11/21] mtd: nand: pxa3xx: Add helper function to set page address Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 12/21] mtd: nand: pxa3xx: Remove READ0 switch/case falltrough Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 13/21] mtd: nand: pxa3xx: Split prepare_command_pool() in two stages Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 14/21] mtd: nand: pxa3xx: Move the data buffer clean to prepare_start_command() Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 15/21] mtd: nand: pxa3xx: Add a read/write buffers markers Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 16/21] mtd: nand: pxa3xx: Introduce multiple page I/O support Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 17/21] mtd: nand: pxa3xx: Add multiple chunk write support Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 18/21] ARM: mvebu: Add a fixed 0Hz clock to represent NAND clock Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 19/21] ARM: mvebu: Add support for NAND controller in Armada 370/XP Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 20/21] ARM: mvebu: Enable NAND controller in Armada XP GP board Ezequiel Garcia
2013-09-19 16:01 ` [PATCH 21/21] ARM: mvebu: Enable NAND controller in Armada 370 Mirabox Ezequiel Garcia
2013-09-19 17:47 ` [PATCH 00/21] Armada 370/XP NAND support Daniel Mack
2013-09-19 18:34   ` Ezequiel Garcia
2013-09-19 21:17   ` Ezequiel Garcia
2013-09-19 21:26     ` Daniel Mack
2013-09-24 18:59 ` Ezequiel Garcia
2013-09-25  6:27   ` Brian Norris
2013-09-25 10:41     ` Ezequiel Garcia
2013-09-26 19:56 ` Brian Norris
2013-09-30 12:24   ` Ezequiel Garcia
2013-10-03  0:02     ` Brian Norris
2013-10-04 19:42       ` Ezequiel Garcia
2013-10-05  0:06         ` Brian Norris
2013-10-16 23:29           ` Ezequiel Garcia

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