On 01/06/15 12:20, David Jander wrote: > qty is the maximum number of discard that _do_ fit in the timeout, not > the first amount that does _not_ fit anymore. > This seemingly harmless error has a very severe performance impact when > the timeout value is enough for only 1 erase group. > > Signed-off-by: David Jander <david@xxxxxxxxxxx> > --- > drivers/mmc/core/core.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 92e7671..1f9573b 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -2234,16 +2234,13 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card, > if (!qty) > return 0; > > - if (qty == 1) > - return 1; > - > /* Convert qty to sectors */ > if (card->erase_shift) > - max_discard = --qty << card->erase_shift; > + max_discard = qty << card->erase_shift; > else if (mmc_card_sd(card)) > max_discard = qty; > else > - max_discard = --qty * card->erase_size; > + max_discard = qty * card->erase_size; > > return max_discard; > } > This keeps coming up but there is more to it than that. See here: http://marc.info/?l=linux-mmc&m=142504164427546 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
