Hi Huang, Artem,
On Sat, 25 Aug 2012 16:06:50 -0400 Huang Shijie <shij...@gmail.com> wrote:
> diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
> index fc960a3..216d751 100644
> --- a/drivers/mtd/cmdlinepart.c
> +++ b/drivers/mtd/cmdlinepart.c
> @@ -322,13 +322,16 @@ static int parse_cmdline_partitions(struct mtd_info
> *master,
> struct cmdline_mtd_partition *part;
> const char *mtd_id = master->name;
>
> + if (!mtd_id)
> + return 0;
> +
> /* parse command line */
> if (!cmdline_parsed)
> mtdpart_setup_real(cmdline);
>
> for(part = partitions; part; part = part->next)
> {
> - if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
> + if (!strcmp(part->mtd_id, mtd_id))
> {
> for(i = 0, offset = 0; i < part->num_parts; i++)
> {
This changes the behavior of cmdling parsing, which might affect users
expecting the old behavior.
According to the remark above 'parse_cmdline_partitions':
* It returns partitions for the requested mtd device, or
* the first one in the chain if a NULL mtd_id is passed in.
I think the purpose of a NULL 'mtd_id' was to support simple systems
where there's a single driver and a single chip.
The driver could be dumb, not specifying its 'mtd_info->name'
(thus, a NULL mtd_id is passed).
In this case, since the system is simply configured (one driver, one
chip), 'parse_cmdline_partitions' simply disregards the "mtd-id" name
specified in the cmdline string, allowing the user to present some
arbitrary string there.
I quite remember seeing this pattern somewhere in the past, I don't know
if it's still used, though.
Obviously if you have many drivers (and many chips) in a system, that
won't work; the drivers must initialize 'mtd_info->name' and the user
should present a cmdline that has explicit 'mtd-id's.
So question is, would we like to prohibit NULL mtd-id?
If so, we must make sure all drivers are properly assigning their
'mtd_info->name', and all users correctly specifying 'mtd-id' in their
"mtdparts" cmdline strings.
Regards,
Shmulik
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