[U-Boot] [PATCH 2/2] fastboot: sparse: remove unnecessary logging

[Steve Rae]

Hi Maxime,

On Mon, Feb 8, 2016 at 12:19 AM, Maxime Ripard <
maxime.ripard at free-electrons.com> wrote:

> Hi Steve,
>
> On Thu, Feb 04, 2016 at 10:51:00AM -0800, Steve Rae wrote:
> > Hi Maxime,
> >
> > On Thu, Feb 4, 2016 at 4:20 AM, Maxime Ripard <
> > maxime.ripard at free-electrons.com> wrote:
> >
> > > Hi Steve,
> > >
> > > On Wed, Feb 03, 2016 at 12:46:02PM -0800, Steve Rae wrote:
> > > > remove logging of the 'skipped' blocks
> > > >
> > > > Signed-off-by: Steve Rae <srae at broadcom.com>
> > > > ---
> > > >
> > > >  common/image-sparse.c | 6 ++----
> > > >  1 file changed, 2 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/common/image-sparse.c b/common/image-sparse.c
> > > > index f02aee4..594bf4e 100644
> > > > --- a/common/image-sparse.c
> > > > +++ b/common/image-sparse.c
> > > > @@ -275,7 +275,6 @@ int store_sparse_image(sparse_storage_t *storage,
> > > void *storage_priv,
> > > >       sparse_buffer_t *buffer;
> > > >       uint32_t start;
> > > >       uint32_t total_blocks = 0;
> > > > -     uint32_t skipped = 0;
> > > >       int i;
> > > >
> > > >       debug("=== Storage ===\n");
> > > > @@ -334,7 +333,6 @@ int store_sparse_image(sparse_storage_t *storage,
> > > void *storage_priv,
> > > >                                                             storage,
> > > >
> > >  sparse_header);
> > > >                       total_blocks += blkcnt;
> > >
> >
> > This change (in the first patch), updates the "total_blocks" value, so
> that
> > the "next" chunk has the proper "starting block" address
> >     (see these line 363...)
> > 362                         ret = storage->write(storage, storage_priv,
> > 363                                              start + total_blocks,
> > 364                                              buffer_blk_cnt,
> > 365                                              buffer->data);
> > Without this change, all the blocks written to the partition after the
> > CHUNK_TYPE_DONT_CARE blocks are corrupted (they are not in the correct
> > location).
> > So, even though we are not actually writing any blocks to this space, the
> > space must be maintained!
>
> Ah, yeah, understood.
>
> I'm guessing it was working in my case since I had no DONT_CARE chunks
> in the first sparse image sent, and then only DONT_CARE chunks for the
> space you already wrote, we got that covered by last_offset... :/
>
> So, yeah, it's broken...
>
> > (Recently, I am now understanding that with NAND, there may be more
> > complications; probably cannot just increment the "total_blocks" -- I
> > suspect that it is required to actually determine if there are bad blocks
> > in this space, and update the "total_blocks" value accordingly....)
>
> Yes, if you try to write to a bad block on NAND, you're actually going
> to write to the next block, which will introduce some offset, or
> you'll going to write to a block that's already been written.
>
> Maxime
>
>
So, to handle MMC versus NAND, I propose that we follow the same method
used throughout 'fastboot':

+#ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
                        total_blocks += blkcnt;
+#endif
+#ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV
+                       /* TBD */
+#endif

What do you think?
I can submit a "v2" -- Could you create a patch for the the NAND part?

Thanks in advance, Steve


> > > -                     skipped += blkcnt;
> > > >                       continue;
> > > >               }
> > > >
> > > > @@ -375,8 +373,8 @@ int store_sparse_image(sparse_storage_t *storage,
> > > void *storage_priv,
> > > >               sparse_put_data_buffer(buffer);
> > > >       }
> > > >
> > > > -     debug("Wrote %d blocks, skipped %d, expected to write %d
> blocks\n",
> > > > -           total_blocks, skipped,
> > > > +     debug("Wrote %d blocks, expected to write %d blocks\n",
> > > > +           total_blocks,
> > >
> > > What's the rationale between those two patches?
> > >
> >
> > see inline comment above
> >
> >
> > >
> > > Do we really want to treat the DONT_CARE chunks as if they were
> > > written?
> > >
> >
> > I suspect that we do, and "sparse_header->total_blks" actually includes
> > them in the count too...
> > This "total_blocks" count is actually the number of blocks "processed"
> > (which may or may not include actually writing to the partition).
> > IMO - I think counting the "skipped blocks is unnecessary.
>
> Ok, sounds good.
>
> Thanks!
> Maxime
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com
>