[U-Boot] [PATCH] spl: if MMCSD_MODE_RAW fails, try MMCSD_MODE_FS, if available

[Guillaume Gardet]

Le 18/02/2016 17:07, Nikita Kiryanov a écrit :
> On Thu, Feb 18, 2016 at 09:36:01AM -0500, Tom Rini wrote:
>> On Thu, Feb 18, 2016 at 04:25:29PM +0200, Nikita Kiryanov wrote:
>>> On Thu, Feb 18, 2016 at 02:31:08PM +0100, Guillaume Gardet wrote:
>>>>
>>>> Le 18/02/2016 14:07, Nikita Kiryanov a écrit :
>>>>> On Thu, Feb 18, 2016 at 11:06:32AM +0100, Guillaume Gardet wrote:
>>>>>> Hi Tom, Nikita ,
>>>>>>
>>>>>> Le 18/02/2016 10:19, Nikita Kiryanov a écrit :
>>>>>>> Hi Tom, Guillaume,
>>>>>>>
>>>>>>> On Wed, Feb 17, 2016 at 03:27:22PM -0500, Tom Rini wrote:
>>>>>>>> On Wed, Feb 17, 2016 at 09:09:27AM +0100, Guillaume GARDET wrote:
>>>>>>>>
>>>>>>>>> Since commit fd61d39970b9901217efc7536d9f3a61b4e1752a:
>>>>>>>>>          spl: mmc: add break statements in spl_mmc_load_image()
>>>>>>>>> RAW and FS boot modes are now exclusive again. So, if MMCSD_MODE_RAW fails, the
>>>>>>>>> board hangs. This patch allows to try MMCSD_MODE_FS then, if available.
>>>>>>>>>
>>>>>>>>> It has been tested on a beaglebone black to boot on an EXT partition.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Guillaume GARDET <guillaume.gardet at free.fr>
>>>>>>>>> Cc: Tom Rini <trini at konsulko.com>
>>>>>>>>> Cc: Nikita Kiryanov <nikita at compulab.co.il>
>>>>>>>>> Cc: Igor Grinberg <grinberg at compulab.co.il>
>>>>>>>>> Cc: Paul Kocialkowski <contact at paulk.fr>
>>>>>>>>> Cc: Pantelis Antoniou <panto at antoniou-consulting.com>
>>>>>>>>> Cc: Simon Glass <sjg at chromium.org>
>>>>>>>>> Cc: Matwey V. Kornilov <matwey.kornilov at gmail.com>
>>>>>>>>>
>>>>>>>>> ---
>>>>>>>>>   common/spl/spl_mmc.c | 2 +-
>>>>>>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>>>>
>>>>>>>>> diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
>>>>>>>>> index c3931c6..2eef0f2 100644
>>>>>>>>> --- a/common/spl/spl_mmc.c
>>>>>>>>> +++ b/common/spl/spl_mmc.c
>>>>>>>>> @@ -284,7 +284,7 @@ int spl_mmc_load_image(u32 boot_device)
>>>>>>>>>   		if (!err)
>>>>>>>>>   			return err;
>>>>>>>>>   #endif
>>>>>>>>> -		break;
>>>>>>>>> +		/* Fall through */
>>>>>>>>>   	case MMCSD_MODE_FS:
>>>>>>>>>   		debug("spl: mmc boot mode: fs\n");
>>>>>>>> This also essentially reverts fd61d399.  So Nikita, was there a specific
>>>>>>>> use case that was broken before, or was the code just unclear in
>>>>>>>> intentions here?  Thanks!
>>>>>>> There was no broken use case that I'm aware of. The change was made as
>>>>>>> part of a code improvement series and was meant to address what I
>>>>>>> consider to be bad and problematic design. Instead of reverting it
>>>>>>> though, how about implementing something similar to what I did in the
>>>>>>> main common/spl/spl.c:board_init_r()? You would have a weak function
>>>>>>> that will default to the original spl_boot_mode() if not overridden,
>>>>>>> and allow the user to define a sequence of boot modes otherwise.
>>>>>> The thing is you broke a wanted behavior currently in use. So, the priority is to come back to the previous behavior.
>>>>> Could you add a comment indicating that this is wanted behavior that
>>>>> has a user, and who the user is?
>>>> Not sure what you mean.
>>> I mean something like:
>>> /* If raw mode fails, try fs mode. Some boards, such as beaglebone black,
>>>   * depend on this funcitonality.
>>>   */
>> But it's not board specific, it's use-case specific.
> The comment I proposed does not suggest it's board specific, just that
> this specific use case is used by someone.
>
>> instead of shoving both SPL and U-Boot into the correct magic raw
>> location, just shove SPL there and let U-Boot itself be in the /boot
>> partition.  This is just as applicable on say imx6 as it is on TI parts.
> I don't think that's clear enough that this is the purpose of the
> missing break statement. It's a little too implicit. What I'm suggesting
> is that we make it a bit more explicit, barring a rewrite.

So, maybe just:
     /* If raw mode fails, try fs mode. */
?


Guillaume

>
>> -- 
>> Tom
>
>