Re: [PATCH v2] mmc : general purpose partition support.

From: Andrei Warkentin
Date: Wed Sep 28 2011 - 12:08:13 EST


Hi Namjae,

In general I think your approach is fine and solves the problem. See further inline
comments.

----- Original Message -----
> From: "Namjae Jeon" <linkinjeon@xxxxxxxxx>
> To: cjb@xxxxxxxxxx, linux-mmc@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx, awarkentin@xxxxxxxxxx, "adrian hunter" <adrian.hunter@xxxxxxxxx>, "james p
> freyensee" <james_p_freyensee@xxxxxxxxxxxxxxx>, "Namjae Jeon" <linkinjeon@xxxxxxxxx>
> Sent: Saturday, September 24, 2011 1:07:00 AM
> Subject: [PATCH v2] mmc : general purpose partition support.
>
> It allows gerneral purpose partitions in MMC Device.
> And I try to simpliy make mmc_blk_alloc_parts using mmc_part
> structure suggested by Andrei Warkentin.
> After patching, we can see general purpose partitions like this.
> > cat /proc/partitions
> 179 0 847872 mmcblk0
> 179 192 4096 mmcblk0gp4
> 179 160 4096 mmcblk0gp3
> 179 128 4096 mmcblk0gp2
> 179 96 1052672 mmcblk0gp1
> 179 64 1024 mmcblk0boot1
> 179 32 1024 mmcblk0boot0
>
> Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxx>

> + if (ext_csd[EXT_CSD_BOOT_MULT]) {
> + for (i = 0, boot_part_config = 0x1;
> + i < MMC_NUM_BOOT_PARTITION;
> + i++, boot_part_config++) {
> + card->part[i].size = ...
> + card->part[i].cookie = ...
> + sprintf(card->part[i].name, "boot%d", i);
> + card->part[i].force_ro = ...
> + }
> + }
> }
>
>
> + if (ext_csd[EXT_CSD_PARTITION_SUPPORT] & 0x1) {
> + ....
> + int i, gp_num, gp_part_config, gp_size_mult;
> + for (i = 2, gp_num = 1, gp_part_config = 0x4,
> + card->part[i].size = ...
> + card->part[i].cookie = ...
> + sprintf(card->part[i].name,
> + "gp%d", gp_num);
> + card->part[i].force_ro = ..
> + }
> + }
>

I feel that you should factor out a function that operates on the static part[] array and
adds a new entry base name, index (i.e. the %d for gp%d), cookie, size, force.
Otherwise you end up with these hidden mines like fixed indeces for
particular parts (i = 2, etc...) which becomes indecipherable for others.
Plus you're mostly doing the same thing.

Thanks,
A
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/