[PATCH v2 2/3] mmc: erase: Use TRIM erase when available

[Loic Poulain]

Hi Jaehoon,

On Mon, 6 Feb 2023 at 06:05, Jaehoon Chung <jh80.chung at samsung.com> wrote:
>
> Hi,
>
> > -----Original Message-----
> > From: Loic Poulain <loic.poulain at linaro.org>
> > Sent: Thursday, January 26, 2023 6:24 PM
> > To: sjg at chromium.org; peng.fan at nxp.com; jh80.chung at samsung.com
> > Cc: u-boot at lists.denx.de; Loic Poulain <loic.poulain at linaro.org>
> > Subject: [PATCH v2 2/3] mmc: erase: Use TRIM erase when available
> >
> > The default erase command applies on erase group unit, and
> > simply round down to erase group size. When the start block
> > is not aligned to erase group size (e.g. erasing partition)
> > it causes unwanted erasing of the previous blocks, part of
> > the same erase group (e.g. owned by other logical partition,
> > or by the partition table itself).
> >
> > To prevent this issue, a simple solution is to use TRIM as
> > argument of the Erase command, which is usually supported
> > with eMMC > 4.0, and allow to apply erase operation to write
> > blocks instead of erase group
> >
> > Signed-off-by: Loic Poulain <loic.poulain at linaro.org>
> > ---
> > v2: Add mmc unit test change to the series
> >
> >  drivers/mmc/mmc_write.c | 34 +++++++++++++++++++++++-----------
> >  1 file changed, 23 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/mmc/mmc_write.c b/drivers/mmc/mmc_write.c
> > index 5b7aeeb012..a6f93380dd 100644
> > --- a/drivers/mmc/mmc_write.c
> > +++ b/drivers/mmc/mmc_write.c
> > @@ -15,7 +15,7 @@
> >  #include <linux/math64.h>
> >  #include "mmc_private.h"
> >
> > -static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt)
> > +static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt, u32 args)
> >  {
> >       struct mmc_cmd cmd;
> >       ulong end;
> > @@ -52,7 +52,7 @@ static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt)
> >               goto err_out;
> >
> >       cmd.cmdidx = MMC_CMD_ERASE;
> > -     cmd.cmdarg = MMC_ERASE_ARG;
> > +     cmd.cmdarg = args ? args : MMC_ERASE_ARG;
>
> It there any case to pass by other value?

Not at the moment, but it can be used to support eMMC 'Secure Erase' arg.

Regards,
Loic