[PATCH] mvebu: bubt: Drop dead code

[Tom Rini]

On Sat, Jul 25, 2020 at 01:38:12PM +0200, Stefan Roese wrote:
> Hi Tom,
> 
> On 24.07.20 23:13, Tom Rini wrote:
> > The code around CONFIG_SYS_MMC_ENV_PART has been untested since merge.
> > This can be seen by it referencing 'mmc->part_num' which was migrated
> > elsewhere prior to this code being merged.
> 
> I'm seeing that CONFIG_SYS_MMC_ENV_PART is also mentioned in the
> documentation for this MVEBU cmd:
> 
> doc/mvebu/cmd/bubt.txt
> 
> So I hesitate a bit to remove it completely from this command (even
> though I personally have never used it). Could you perhaps send me a
> link a patch / commit, where 'mmc->part_num' has been migrated?

It was changed in:
commit 873cc1d7775ed5de07e6722c7ff423080c2e8f71
Author:     Stephen Warren <swarren at nvidia.com>
AuthorDate: Mon Dec 7 11:38:49 2015 -0700
Commit:     Tom Rini <trini at konsulko.com>
CommitDate: Wed Jan 13 21:05:19 2016 -0500

    mmc: store hwpart in the block device
    
    This will allow us to have multiple block device structs each referring
    to the same eMMC device, yet different HW partitions.
    
    For now, there is still a single block device per eMMC device. As before,
    this block device always accesses whichever HW partition was most recently
    selected. Clients wishing to make use of multiple block devices referring
    to different HW partitions can simply take a copy of this block device
    once it points at the correct HW partition, and use each one as they wish.
    This feature will be used by the next patch.
    
    In the future, perhaps get_device() could be enhanced to return a
    dynamically allocated block device struct, to avoid the client needing to
    copy it in order to maintain multiple block devices. However, this would
    require all users to be updated to free those block device structs at some
    point, which is rather a large change.
    
    Most callers of mmc_switch_part() wish to permanently switch the default
    MMC block device's HW partition. Enhance mmc_switch_part() so that it does
    this. This removes the need for callers to do this. However,
    common/env_mmc.c needs to save and restore the current HW partition. Make
    it do this more explicitly.
    
    Replace use of mmc_switch_part() with mmc_select_hwpart() in order to
    remove duplicate code that skips the call if that HW partition is already
    selected.
    
    Signed-off-by: Stephen Warren <swarren at nvidia.com>
    Reviewed-by: Tom Rini <trini at konsulko.com>

Which is before cmd/mvebu/bubt.c was added to mainline.  So while I'm
sure the command worked in the downstream tree, it wasn't ever tested in
mainline.  It also means that changing it to mmc->block_dev.hwpart
instead of mmc->part_num would also work, but the code would remain
untested.  Note that I ran in to this in moving
CONFIG_SYS_MMC_ENV_PART/DEV to Kconfig and that leading to us always
having these variables set to at least 0, so if you're going to fix the
code to build please keep that in mind as well and that would should
probably drop the #if check and always change to the correct dev/part.
Thanks!

-- 
Tom
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