Hi Wolfram,
On 2017/8/17 18:40, Wolfram Sang wrote:
Hi Shawn,
On Wed, Aug 16, 2017 at 09:11:41AM +0800, Shawn Lin wrote:
We to some extent should tolerate R1_OUT_OF_RANGE for open-ending
mode as it is expected behaviour and most of the backup partition
tables should be located near some of the last blocks which will
always make open-ending read exceed the capacity of cards.
Fixes: 9820a5b11101 ("mmc: core: for data errors, take response of stop cmd into account")
Fixes: a04e6bae9e6f ("mmc: core: check also R1 response for stop commands")
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Tested-by: Shawn Guo <shawnguo@xxxxxxxxxx>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
I'd think these Tested-by should be dropped. We changed the patch quite
a bit meanwhile and I am quite sure Shimoda-san didn't test this new
version of the patch. Dunno about Shawn. Hopefully they have time to
re-test?
+ /*
+ * Per the SD specification(physical layer version 4.10)[1],
+ * section 4.3.3, it explicitly states that "When the last
+ * block of user area is read using CMD18, the host should
+ * ignore OUT_OF_RANGE error that may occur even the sequence
+ * is correct". And JESD84-B51 for eMMC also has a similar
+ * statement on section 6.8.3.
+ *
+ * Multiple block read/write could be done by either predefined
+ * method, namely CMD23, or open-ending mode.
+ *
Very minor nit: I'd remove this empty line and merge the two paragraphs.
well do in v4
+ * For open-ending mode, we should ignore the OUT_OF_RANGE
+ * error as it's normal behaviour.
+ *
+ * However the spec[1] doesn't tell us whether we should also
+ * ignore that for predefined method. But per the spec[1], section
+ * 4.15 Set Block Count Command, it says"If illegal block count
+ * is set, out of range error will be indicated during read/write
+ * operation (For example, data transfer is stopped at user area
+ * boundary)." In another word, we could expect a out of range error
+ * in the response for the following CMD18/25. And if argument of
+ * CMD23 + the argument of CMD18/25 exceed the max number of blocks,
+ * we could also expect to get a -ETIMEDOUT or any error number from
+ * the host drivers due to missing data response(for write)/data(for
+ * read), as the cards will stop the data transfer by itself per the
+ * spec. So we only need to check R1_OUT_OF_RANGE for open-ending mode.
+ */
Very good! I like this a lot.
Also minor nit, but likely better readable:
+
+ if (!brq->stop.error) {
bool OOR_with_open_end;
+ /* If there is no error yet, check R1 response */
+ val = brq->stop.resp[0] & CMD_ERRORS;
OOR_with_open_end = val & R1_OUT_OF_RANGE && !brq->mrq.sbc;
if (val && !OOR_with_open_end)
+ brq->stop.error = -EIO;
...
+ if (brq->sbc.error || brq->cmd.error ||
+ brq->stop.error || brq->data.error) {
will do in v4 but slightly rename it to oor_with_open_end as
it doesn't seem general to name a variable with upper letter.
I am not super strict with the 80 char limit and think one line is
better readable, but I leave that to you and/or Ulf.
Make sense but I will keep it and leave that to Ulf too. :)
Other than that minor stuff:
Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Thanks for this collaboration! I liked it :)
Regards,
Wolfram
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