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

[Nikita Kiryanov <nikita@compulab.co.il>]

On Thu, Feb 18, 2016 at 05:11:46PM +0100, Guillaume Gardet wrote:
> 
> 
> Le 18/02/2016 17:07, Nikita Kiryanov a ?crit :
> >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 ?crit :
> >>>>>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 ?crit :
> >>>>>>>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@free.fr>
> >>>>>>>>>Cc: Tom Rini <trini@konsulko.com>
> >>>>>>>>>Cc: Nikita Kiryanov <nikita@compulab.co.il>
> >>>>>>>>>Cc: Igor Grinberg <grinberg@compulab.co.il>
> >>>>>>>>>Cc: Paul Kocialkowski <contact@paulk.fr>
> >>>>>>>>>Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
> >>>>>>>>>Cc: Simon Glass <sjg@chromium.org>
> >>>>>>>>>Cc: Matwey V. Kornilov <matwey.kornilov@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. */
> ?

That'll work too.

> 
> 
> Guillaume
> 
> >
> >>-- 
> >>Tom
> >
> >
>