Hi Sjoerd,
On Tuesday 06 November 2018 07:00 PM, Sjoerd Simons wrote:
> On some of our boards containing Micron eMMC chips compatible with
> the eMMC 5.0 specification we starting seeing boot failures due to
> timeouts:
> mmc1: error -110 whilst initialising MMC card
>
> It turns out that switching the cache on after a power loss event can
> take quite long. In some simple testing thusfar we've seen values up to
> 700ms, which is far longer then the GENERIC_CMD6_TIME of the chip
> (250ms).
>
> Looking at both the eMMC 4.51 and 5.0 specification there doesn't seem
> to be a defined upper bound for the CACHE_CTRL ON command. For both
> CACHE_CTRL OFF and FLUSH_CACHE it is documented that they can take
> essentially unbounded time, but CACHE_CTRL ON i get the impression that
> it's assumed to be "fast". Unfortunately this is not true in reality.
>
> To resolve this, simply drop the timeout from CACHE_CTRL ON and assume
> it might take an unbounded time similar to the FLUSH_CACHE command.
>
> Signed-off-by: Sjoerd Simons <sjoerd.simons@xxxxxxxxxxxxxxx>
>
I have the exact same problem with micron cards. Specifically with CID:
R1J56L
The correct way to solve this would be to add a quirk for the specific
card. Does this patch solve your issue?
---8<---
>From 9d470be59acd82859beb4c965a620c9a32858bb4 Mon Sep 17 00:00:00 2001
From: Faiz Abbas <faiz_abbas@xxxxxx>
Date: Wed, 20 Jun 2018 20:36:38 +0530
Subject: [PATCH] mmc: core: Add QUIRK for eMMC CMD6 timeout for some Micron
cards
It seems that on some Micron eMMC cards present on TI's AM654 EVM
the CACHE_CTRL_ENABLE function in CMD6 takes longer (~750 ms) than
the specified timeout in the GENERIC_CMD6_TIMEOUT byte of the
Extended CSD (~250 ms).
Therefore, add a quirk to detect this card and use a value of 1 sec for
timeout.
Reported-by: Andreas Dannenberg <dannenberg@xxxxxx>
Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
---
drivers/mmc/core/card.h | 7 +++++++
drivers/mmc/core/mmc.c | 14 +++++++++++++-
drivers/mmc/core/quirks.h | 8 ++++++++
include/linux/mmc/card.h | 1 +
4 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h
index 9c821eedd156..6b5e3c6253f5 100644
--- a/drivers/mmc/core/card.h
+++ b/drivers/mmc/core/card.h
@@ -84,6 +84,8 @@ struct mmc_fixup {
#define CID_MANFID_HYNIX 0x90
#define CID_MANFID_NUMONYX 0xFE
+#define CID_NAME_R1J56L "R1J56L"
+
#define END_FIXUP { NULL }
#define _FIXUP_EXT(_name, _manfid, _oemid, _rev_start, _rev_end, \
@@ -221,4 +223,9 @@ static inline int mmc_card_broken_hpi(const struct mmc_card *c)
return c->quirks & MMC_QUIRK_BROKEN_HPI;
}
+static inline int mmc_card_long_cache_ctrl(const struct mmc_card *c)
+{
+ return c->quirks & MMC_QUIRK_LONG_CACHE_ENABLE_TIME;
+}
+
#endif
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index bad5c1bf4ed9..667caeb640a3 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1522,6 +1522,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
struct mmc_card *oldcard)
{
struct mmc_card *card;
+ unsigned int cache_ctrl_timeout;
int err;
u32 cid[4];
u32 rocr;
@@ -1766,9 +1767,20 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
*/
if (!mmc_card_broken_hpi(card) &&
card->ext_csd.cache_size > 0) {
+
+ /*
+ * Some cards require a longer timeout than given in CSD.
+ * Use a one second timeout here which can be increased
+ * further if more cards needing larger timeouts are found
+ */
+ if (mmc_card_long_cache_ctrl(card))
+ cache_ctrl_timeout = 1000;
+ else
+ cache_ctrl_timeout = card->ext_csd.generic_cmd6_time;
+
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_CACHE_CTRL, 1,
- card->ext_csd.generic_cmd6_time);
+ cache_ctrl_timeout);
if (err && err != -EBADMSG)
goto free_card;
diff --git a/drivers/mmc/core/quirks.h b/drivers/mmc/core/quirks.h
index 5153577754f0..934ca72ef2b1 100644
--- a/drivers/mmc/core/quirks.h
+++ b/drivers/mmc/core/quirks.h
@@ -116,6 +116,14 @@ static const struct mmc_fixup mmc_ext_csd_fixups[] = {
MMC_FIXUP_EXT_CSD_REV(CID_NAME_ANY, CID_MANFID_NUMONYX,
0x014e, add_quirk, MMC_QUIRK_BROKEN_HPI, 6),
+ /*
+ * Certain Micron eMMC cards need a longer CMD6:CACHE_CTRL timeout
+ * than indicated in CSD
+ */
+ MMC_FIXUP_EXT_CSD_REV(CID_NAME_R1J56L, CID_MANFID_MICRON,
+ 0x14e, add_quirk,
+ MMC_QUIRK_LONG_CACHE_ENABLE_TIME, 7),
+
END_FIXUP
};
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 279b39008a33..5a8ce0bb222e 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -268,6 +268,7 @@ struct mmc_card {
#define MMC_QUIRK_BROKEN_IRQ_POLLING (1<<11) /* Polling SDIO_CCCR_INTx could create a fake interrupt */
#define MMC_QUIRK_TRIM_BROKEN (1<<12) /* Skip trim */
#define MMC_QUIRK_BROKEN_HPI (1<<13) /* Disable broken HPI support */
+#define MMC_QUIRK_LONG_CACHE_ENABLE_TIME (1 << 14) /* CACHE_CTRL enable time > CSD says */
bool reenable_cmdq; /* Re-enable Command Queue */
--
2.18.0
Thanks,
Faiz
