Signed-off-by: David Jander <da...@protonic.nl>
---
drivers/mmc/core/core.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 6c9611b..b6aa9ad 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2109,11 +2109,20 @@ int mmc_erase(struct mmc_card *card, unsigned int from,
unsigned int nr,
!(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
return -EOPNOTSUPP;
+ /*
+ * Sanity check: If we do not erase aligned, whole erase-groups, return
+ * an error, since we intended a "secure" erase, silently not erasing
+ * something would be unacceptable.
+ */
if (arg == MMC_SECURE_ERASE_ARG) {
if (from % card->erase_size || nr % card->erase_size)
return -EINVAL;
}
+ /*
+ * Make sure only erase-groups that are fully contained in the erase
+ * region are erased. Silently ignore the rest.
+ */
if (arg == MMC_ERASE_ARG) {
rem = from % card->erase_size;
if (rem) {
@@ -2140,6 +2149,14 @@ int mmc_erase(struct mmc_card *card, unsigned int from,
unsigned int nr,
/* 'from' and 'to' are inclusive */
to -= 1;
+ /*
+ * Special case where only one erase-group fits in the timout budget:
+ * If the region crosses an erase-group boundary on this particular
+ * case, we will be trimming more than one erase-group which, does not
+ * fit in the timeout budget of the controller, so we need to split it
+ * and call mmc_do_erase() twice if necessary. This special case is
+ * identified by the card->eg_boundary flag.
+ */
if ((arg & MMC_TRIM_ARGS) && (card->eg_boundary) &&
(from % card->erase_size)) {
rem = card->erase_size - (from % card->erase_size);
@@ -2244,7 +2261,16 @@ static unsigned int mmc_do_calc_max_discard(struct
mmc_card *card,
if (!qty)
return 0;
- /* We can only erase one erase group special case */
+ /*
+ * When specifying a sector range to trim, chances are we might cross
+ * an erase-group boundary even if the amount of sectors is less than
+ * one erase-group.
+ * If we can only fit one erase-group in the controller timeout budget,
+ * we have to care that erase-group boundaries are not crossed by a
+ * single trim operation. We flag that special case with "eg_boundary".
+ * In all other cases we can just decrement qty and pretend that we
+ * always touch (qty + 1) erase-groups as a simple optimization.
+ */
if (qty == 1)
card->eg_boundary = 1;
else
--
2.1.4
--
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