linux-kernel - Re: [PATCH 5/5] mtd: rawnand: qcom: reorganization by removing read/write helpers

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Date:   Wed, 18 Jul 2018 23:29:45 +0200
From:   Miquel Raynal <miquel.raynal@...tlin.com>
To:     Abhishek Sahu <absahu@...eaurora.org>
Cc:     Boris Brezillon <boris.brezillon@...tlin.com>,
        David Woodhouse <dwmw2@...radead.org>,
        Brian Norris <computersforpeace@...il.com>,
        Marek Vasut <marek.vasut@...il.com>,
        Richard Weinberger <richard@....at>,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-mtd@...ts.infradead.org, Andy Gross <andy.gross@...aro.org>
Subject: Re: [PATCH 5/5] mtd: rawnand: qcom: reorganization by removing
 read/write helpers

Hi Abhishek,

Abhishek Sahu <absahu@...eaurora.org> wrote on Fri,  6 Jul 2018
13:21:59 +0530:

> Driver does not send the commands to NAND device for page
> read/write operations in ->cmdfunc(). It just does some
> minor variable initialization and rest of the things
> are being done in actual ->read/write_oob[_raw].

Thank you for cleaning actively this driver. I think you are comfortable
enough now to switch to start the migration to ->exec_op().

I will take this patch as I think it shrinks a bit the driver (which is
inordinately huge) but I would like to get rid of any kind of hackish
->cmdfunc() implementation. Boris and I can help you doing that, you
can grep for drivers already converted and observe they structure
(marvell, fsmc, vf610).

> 
> The generic helper function calls for invoking commands during
> page read/write are making this driver complicated. For QCOM NAND
> driver, ->cmdfunc() does minor part of initialization and rest of
> the initialization is performed by actual page read/write
> functions. Also, ->read/write_oob() does not calls helper
> function and all the initialization is being done in
> ->read/write_oob() itself.  
> 
> Since after 'commit 25f815f66a14 ("mtd: nand: force drivers to
> explicitly send READ/PROG commands")', sending of commands has
> been moved to driver for page read/write, so this patch does
> following changes to make code more readable:
> 
> 1. Introduce qcom_nand_init_page_op() and qcom_nand_start_page_op()
>    helper functions which helps in removing code duplication in each
>    operation.
> 
> 2. After issuing PROGRAM PAGE/BLOCK ERASE, QCOM NAND
>    controller waits for BUSY signal to be de asserted and
>    automatically issues the READ STATUS command. Currently, driver
>    is storing this status privately and returns the same when status
>    command comes from helper function after program/erase operation.
>    Now, for write operations, the status can be returned from main
>    function itself, so storing status can be removed for program
>    operations.
> 
> Signed-off-by: Abhishek Sahu <absahu@...eaurora.org>
> ---

Thanks,
Miquèl