Subject: Re: [PATCH] mtd: powernv: SPDX and comment fixups

From: Boris Brezillon <[email-masked]>
Date: Thu, 7 Feb 2019 09:37:34 +0100

Hello Joel,

On Wed,  6 Feb 2019 11:06:58 +1030
Joel Stanley <[email-masked]> wrote:

> This converts the powernv flash driver to use SPDX, and adds some
> clarifying comments that came out of a discussion on how the mtd driver
> works.

Can you split that in 2 patches, one adding the SPDX header, and the
other one clarifying the driver behavior.

Thanks,

Boris

> 
> Signed-off-by: Joel Stanley <[email-masked]>
> ---
>  drivers/mtd/devices/powernv_flash.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c
> index 22f753e555ac..0bf43336c3f7 100644
> --- a/drivers/mtd/devices/powernv_flash.c
> +++ b/drivers/mtd/devices/powernv_flash.c
> @@ -1,17 +1,9 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
>  /*
>   * OPAL PNOR flash MTD abstraction
>   *
>   * Copyright IBM 2015
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License as published by
> - * the Free Software Foundation; either version 2 of the License, or
> - * (at your option) any later version.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> - * GNU General Public License for more details.
>   */
>  
>  #include <linux/kernel.h>
> @@ -261,6 +253,14 @@ static int powernv_flash_probe(struct platform_device *pdev)
>  	 * The current flash that skiboot exposes is one contiguous flash chip
>  	 * with an ffs partition at the start, it should prove easier for users
>  	 * to deal with partitions or not as they see fit
> +	 *
> +	 * When developing the skiboot MTD driver an experiment with FFS
> +	 * parsing in the kernel, and exposing a seperate /dev/mtdX for each
> +	 * partition (eg BOOTKERNEL, PAYLOAD, NVRAM, etc), was done.
> +	 *
> +	 * We didn't go with that as it meant users couldn't do a full flash
> +	 * re-write, as this can cause a partition to change size, and there
> +	 * wasn't a way to tell the MTD layer that a device has shrunk/grown.
>  	 */
>  	return mtd_device_register(&data->mtd, NULL, 0);
>  }