On 6/09/2016 9:26 a.m., Baolin Wang wrote:
Hi Andreas,
On 6 September 2016 at 12:34, Andreas Mohr <andi@xxxxxxxx> wrote:
On Tue, Sep 06, 2016 at 10:55:11AM +0800, Baolin Wang wrote:
In order to clean up the mmc_erase() function and do some optimization
for erase size alignment, factor out the guts of erase size alignment
into mmc_align_erase_size() function.
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
Tested-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
drivers/mmc/core/core.c | 60 +++++++++++++++++++++++++++++------------------
1 file changed, 37 insertions(+), 23 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 7d7209d..5f93eef 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2202,6 +2202,37 @@ out:
return err;
}
+static unsigned int mmc_align_erase_size(struct mmc_card *card,
+ unsigned int *from,
+ unsigned int *to,
+ unsigned int nr)
+{
+ unsigned int from_new = *from, nr_new = nr, rem;
+
+ rem = from_new % card->erase_size;
+ if (rem) {
+ rem = card->erase_size - rem;
+ from_new += rem;
+ if (nr_new > rem)
+ nr_new -= rem;
+ else
+ return 0;
+ }
+
+ rem = nr_new % card->erase_size;
+ if (rem)
+ nr_new -= rem;
+
+ if (nr_new == 0)
+ return 0;
+
+ /* 'from' and 'to' are inclusive */
+ *to = from_new + nr_new - 1;
+ *from = from_new;
+
+ return nr_new;
+}
+
/**
* mmc_erase - erase sectors.
* @card: card to erase
@@ -2234,31 +2265,14 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
}
if (arg == MMC_ERASE_ARG) {
- rem = from % card->erase_size;
- if (rem) {
- rem = card->erase_size - rem;
- from += rem;
- if (nr > rem)
- nr -= rem;
- else
- return 0;
- }
- rem = nr % card->erase_size;
- if (rem)
- nr -= rem;
+ nr = mmc_align_erase_size(card, &from, &to, nr);
+ if (nr == 0)
+ return 0;
+ } else {
+ /* 'from' and 'to' are inclusive */
+ to -= 1;
}
- if (nr == 0)
- return 0;
-
- to = from + nr;
-
- if (to <= from)
- return -EINVAL;
Hmm, this is swallowing -EINVAL behaviour
i.e., now possibly violating protocol?
I didn't see what situation will make variable 'to' is less than
'from' since I think variable 'nr' is always larger than 0, right? If
so, we should remove this useless checking. Thanks.
It is checking overflows.
(this may easily be ok - haven't done an extensive review -
but since the commit has that characteristic change,
the commit message should contain that detail)
Thanks for the cleanup work & HTH,
Andreas Mohr
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