[U-Boot] [PATCH] mmc: dw_mmc: Round up descriptor end to nearest multiple of cacheline size

[Simon Glass]

Hi Marek,

On Sat, 30 Mar 2019 at 20:37, Marek Vasut <marex at denx.de> wrote:
>
> On 3/30/19 10:18 PM, Simon Glass wrote:
> > Hi Marek,
> >
> > On Sat, 23 Mar 2019 at 11:55, Marek Vasut <marex at denx.de> wrote:
> >>
> >> The driver currently calculates the end address of cache flush operation
> >> for the DMA descriptors by adding cacheline size to the start address of
> >> the last DMA descriptor. This is not safe, as the cacheline size may be,
> >> in some unlikely cases, smaller than the DMA descriptor size. Replace the
> >> addition with roundup() applied on the end address of the last DMA
> >> descriptor to round it up to the nearest cacheline size multiple.
> >>
> >> Signed-off-by: Marek Vasut <marex at denx.de>
> >> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> >> Cc: Simon Glass <sjg at chromium.org>
> >> ---
> >>  drivers/mmc/dw_mmc.c | 4 ++--
> >>  1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
> >> index 72570235cb..bec30b1479 100644
> >> --- a/drivers/mmc/dw_mmc.c
> >> +++ b/drivers/mmc/dw_mmc.c
> >> @@ -74,15 +74,15 @@ static void dwmci_prepare_data(struct dwmci_host *host,
> >>                 dwmci_set_idma_desc(cur_idmac, flags, cnt,
> >>                                     (ulong)bounce_buffer + (i * PAGE_SIZE));
> >>
> >> +               cur_idmac++;
> >
> > What is this change for? I don't see it mentioned above.
>
> AFAIR you need to increment the pointer to cur_idmac before breaking out
> of the loop, otherwise data_end might point a bit before the actual end
> of the buffer.

OK is that fixing a bug? Should it be in a different commit, or
mentioned in this commit message?

Regards,
Simon