[PATCH v2 0/2] mmc: core: Extend manufacturing date beyond 2025

[PATCH v2 0/2] mmc: core: Extend manufacturing date beyond 2025

[Avri Altman]

Hi Ulf,

This patch series addresses the upcoming exhaustion of the eMMC
manufacturing date (MDT) year field, which is limited to a 4-bit value
in the CID register. Under the current standard (EXT_CSD_REV=8), the
representable years end in 2025.

The first patch implements the recently approved JEDEC standard update
for EXT_CSD_REV=9. This update rolls over the 4-bit year codes to cover
a new 16-year period, extending the range up to 2038.

The second patch introduces a quirk to handle vendor-specific behavior.
Some eMMC vendors are not yet updating their devices to EXT_CSD_REV=9
but still need to report manufacturing dates for 2026 and beyond. These
devices re-purpose the year codes for 2010-2012 to represent 2026-2028.

Thanks,
Avri

---
Changes in v2:
- move the fixup to `mmc_ext_csd_fixups`
- State the correct spec release
- Fixed a typo in the commit message of the second patch.
---

Avri Altman (2):
  mmc: core: Adjust MDT beyond 2025
  mmc: core: Add quirk for incorrect manufacturing date

 drivers/mmc/core/card.h   |  6 ++++++
 drivers/mmc/core/mmc.c    | 12 ++++++++++++
 drivers/mmc/core/quirks.h |  3 +++
 include/linux/mmc/card.h  |  1 +
 4 files changed, 22 insertions(+)

-- 
2.34.1

[PATCH v2 1/2] mmc: core: Adjust MDT beyond 2025

[Avri Altman]

JEDEC JESD84-B51B which was released in September 2025, increases the
manufacturing year limit for eMMC devices. The eMMC manufacturing year
is stored in a 4-bit field in the CID register. Originally, it covered
1997–2012. Later, with EXT_CSD_REV=8, it was extended up to 2025. Now,
with EXT_CSD_REV=9, the range is rolled over by another 16 years, up to
2038.

The mapping is as follows:
cid[8..11] | rev ≤ 4 | 8 ≥ rev > 4 | rev > 8
---------------------------------------------
0          | 1997    | 2013        | 2029
1          | 1998    | 2014        | 2030
2          | 1999    | 2015        | 2031
3          | 2000    | 2016        | 2032
4          | 2001    | 2017        | 2033
5          | 2002    | 2018        | 2034
6          | 2003    | 2019        | 2035
7          | 2004    | 2020        | 2036
8          | 2005    | 2021        | 2037
9          | 2006    | 2022        | 2038
10         | 2007    | 2023        |
11         | 2008    | 2024        |
12         | 2009    | 2025        |
13         | 2010    |             | 2026
14         | 2011    |             | 2027
15         | 2012    |             | 2028

Signed-off-by: Avri Altman <avri.altman@sandisk.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
---
 drivers/mmc/core/mmc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 7c86efb1044a..f744dd501842 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -671,7 +671,14 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
 		card->ext_csd.enhanced_rpmb_supported =
 					(card->ext_csd.rel_param &
 					 EXT_CSD_WR_REL_PARAM_EN_RPMB_REL_WR);
+
+		if (card->ext_csd.rev >= 9) {
+			/* Adjust production date as per JEDEC JESD84-B51B September 2025 */
+			if (card->cid.year < 2023)
+				card->cid.year += 16;
+		}
 	}
+
 out:
 	return err;
 }
-- 
2.34.1

[PATCH v2 2/2] mmc: core: Add quirk for incorrect manufacturing date

[Avri Altman]

Some eMMC vendors need to report manufacturing dates beyond 2025 but are
reluctant to update the EXT_CSD revision from 8 to 9. Changing the
Updating the EXT_CSD revision may involve additional testing or
qualification steps with customers. To ease this transition and avoid a
full re-qualification process, a workaround is needed. This
patch introduces a temporary quirk that re-purposes the year codes
corresponding to 2010, 2011, and 2012 to represent the years 2026, 2027,
and 2028, respectively. This solution is only valid for this three-year
period.

After 2028, vendors must update their firmware to set EXT_CSD_REV=9 to
continue reporting the correct manufacturing date in compliance with the
JEDEC standard.

The `MMC_QUIRK_BROKEN_MDT` is introduced and enabled for all Sandisk
devices to handle this behavior.

Signed-off-by: Avri Altman <avri.altman@sandisk.com>
---
 drivers/mmc/core/card.h   | 6 ++++++
 drivers/mmc/core/mmc.c    | 5 +++++
 drivers/mmc/core/quirks.h | 3 +++
 include/linux/mmc/card.h  | 1 +
 4 files changed, 15 insertions(+)

diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h
index 1200951bab08..a9619dd45270 100644
--- a/drivers/mmc/core/card.h
+++ b/drivers/mmc/core/card.h
@@ -89,6 +89,7 @@ struct mmc_fixup {
 #define CID_MANFID_MICRON       0x13
 #define CID_MANFID_SAMSUNG      0x15
 #define CID_MANFID_APACER       0x27
+#define CID_MANFID_SANDISK_MMC  0x45
 #define CID_MANFID_SWISSBIT     0x5D
 #define CID_MANFID_KINGSTON     0x70
 #define CID_MANFID_HYNIX	0x90
@@ -305,4 +306,9 @@ static inline int mmc_card_no_uhs_ddr50_tuning(const struct mmc_card *c)
 	return c->quirks & MMC_QUIRK_NO_UHS_DDR50_TUNING;
 }
 
+static inline int mmc_card_broken_mdt(const struct mmc_card *c)
+{
+	return c->quirks & MMC_QUIRK_BROKEN_MDT;
+}
+
 #endif
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f744dd501842..8846550a8892 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -676,6 +676,11 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
 			/* Adjust production date as per JEDEC JESD84-B51B September 2025 */
 			if (card->cid.year < 2023)
 				card->cid.year += 16;
+		} else {
+			/* Handle vendors with broken MDT reporting */
+			if (mmc_card_broken_mdt(card) && card->cid.year >= 2010 &&
+			    card->cid.year <= 2012)
+				card->cid.year += 16;
 		}
 	}
 
diff --git a/drivers/mmc/core/quirks.h b/drivers/mmc/core/quirks.h
index c417ed34c057..f5e8a0f6d11b 100644
--- a/drivers/mmc/core/quirks.h
+++ b/drivers/mmc/core/quirks.h
@@ -170,6 +170,9 @@ static const struct mmc_fixup __maybe_unused mmc_ext_csd_fixups[] = {
 	MMC_FIXUP_EXT_CSD_REV(CID_NAME_ANY, CID_MANFID_NUMONYX,
 			      0x014e, add_quirk, MMC_QUIRK_BROKEN_HPI, 6),
 
+	MMC_FIXUP(CID_NAME_ANY, CID_MANFID_SANDISK_MMC, CID_OEMID_ANY, add_quirk_mmc,
+		  MMC_QUIRK_BROKEN_MDT),
+
 	END_FIXUP
 };
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index e9e964c20e53..4722dd7e46ce 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -329,6 +329,7 @@ struct mmc_card {
 #define MMC_QUIRK_BROKEN_CACHE_FLUSH	(1<<16)	/* Don't flush cache until the write has occurred */
 #define MMC_QUIRK_BROKEN_SD_POWEROFF_NOTIFY	(1<<17) /* Disable broken SD poweroff notify support */
 #define MMC_QUIRK_NO_UHS_DDR50_TUNING	(1<<18) /* Disable DDR50 tuning */
+#define MMC_QUIRK_BROKEN_MDT    (1<<19) /* Wrong manufacturing year */
 
 	bool			written_flag;	/* Indicates eMMC has been written since power on */
 	bool			reenable_cmdq;	/* Re-enable Command Queue */
-- 
2.34.1

RE: [PATCH v2 0/2] mmc: core: Extend manufacturing date beyond 2025

[Avri Altman]

> Hi Ulf,
> 
> This patch series addresses the upcoming exhaustion of the eMMC manufacturing
> date (MDT) year field, which is limited to a 4-bit value in the CID register. Under
> the current standard (EXT_CSD_REV=8), the representable years end in 2025.
> 
> The first patch implements the recently approved JEDEC standard update for
> EXT_CSD_REV=9. This update rolls over the 4-bit year codes to cover a new 16-
> year period, extending the range up to 2038.
> 
> The second patch introduces a quirk to handle vendor-specific behavior.
> Some eMMC vendors are not yet updating their devices to EXT_CSD_REV=9 but
> still need to report manufacturing dates for 2026 and beyond. These devices re-
> purpose the year codes for 2010-2012 to represent 2026-2028.
Ulf hi,
Would appreciate if you could look at this before year end.

Thanks,
Avri


> 
> Thanks,
> Avri
> 
> ---
> Changes in v2:
> - move the fixup to `mmc_ext_csd_fixups`
> - State the correct spec release
> - Fixed a typo in the commit message of the second patch.
> ---
> 
> Avri Altman (2):
>   mmc: core: Adjust MDT beyond 2025
>   mmc: core: Add quirk for incorrect manufacturing date
> 
>  drivers/mmc/core/card.h   |  6 ++++++
>  drivers/mmc/core/mmc.c    | 12 ++++++++++++
>  drivers/mmc/core/quirks.h |  3 +++
>  include/linux/mmc/card.h  |  1 +
>  4 files changed, 22 insertions(+)
> 
> --
> 2.34.1

Re: [PATCH v2 0/2] mmc: core: Extend manufacturing date beyond 2025

[Ulf Hansson]

On Mon, 8 Dec 2025 at 10:34, Avri Altman <Avri.Altman@sandisk.com> wrote:
>
> > Hi Ulf,
> >
> > This patch series addresses the upcoming exhaustion of the eMMC manufacturing
> > date (MDT) year field, which is limited to a 4-bit value in the CID register. Under
> > the current standard (EXT_CSD_REV=8), the representable years end in 2025.
> >
> > The first patch implements the recently approved JEDEC standard update for
> > EXT_CSD_REV=9. This update rolls over the 4-bit year codes to cover a new 16-
> > year period, extending the range up to 2038.
> >
> > The second patch introduces a quirk to handle vendor-specific behavior.
> > Some eMMC vendors are not yet updating their devices to EXT_CSD_REV=9 but
> > still need to report manufacturing dates for 2026 and beyond. These devices re-
> > purpose the year codes for 2010-2012 to represent 2026-2028.
> Ulf hi,
> Would appreciate if you could look at this before year end.

The series looks good to me. I will apply it as soon as we have the v6.19-rc1.

[...]

Kind regards
Uffe

Re: [PATCH v2 0/2] mmc: core: Extend manufacturing date beyond 2025

[Ulf Hansson]

On Fri, 28 Nov 2025 at 06:20, Avri Altman <avri.altman@gmail.com> wrote:
>
> Hi Ulf,
>
> This patch series addresses the upcoming exhaustion of the eMMC
> manufacturing date (MDT) year field, which is limited to a 4-bit value
> in the CID register. Under the current standard (EXT_CSD_REV=8), the
> representable years end in 2025.
>
> The first patch implements the recently approved JEDEC standard update
> for EXT_CSD_REV=9. This update rolls over the 4-bit year codes to cover
> a new 16-year period, extending the range up to 2038.
>
> The second patch introduces a quirk to handle vendor-specific behavior.
> Some eMMC vendors are not yet updating their devices to EXT_CSD_REV=9
> but still need to report manufacturing dates for 2026 and beyond. These
> devices re-purpose the year codes for 2010-2012 to represent 2026-2028.
>
> Thanks,
> Avri
>
> ---
> Changes in v2:
> - move the fixup to `mmc_ext_csd_fixups`
> - State the correct spec release
> - Fixed a typo in the commit message of the second patch.
> ---
>
> Avri Altman (2):
>   mmc: core: Adjust MDT beyond 2025
>   mmc: core: Add quirk for incorrect manufacturing date
>
>  drivers/mmc/core/card.h   |  6 ++++++
>  drivers/mmc/core/mmc.c    | 12 ++++++++++++
>  drivers/mmc/core/quirks.h |  3 +++
>  include/linux/mmc/card.h  |  1 +
>  4 files changed, 22 insertions(+)
>
> --
> 2.34.1
>

I have applied the series for next, thanks!

However, I noticed that the author of the patch has your gmail-address
and the sob has your sandisk-address. I guess we should change to your
sandisk-address to be in both places, no?

Kind regards
Uffe

RE: [PATCH v2 0/2] mmc: core: Extend manufacturing date beyond 2025

[Avri Altman]

> I have applied the series for next, thanks!
> 
> However, I noticed that the author of the patch has your gmail-address and the
> sob has your sandisk-address. I guess we should change to your sandisk-address
> to be in both places, no?
Yes. Sorry for missing this.

Thanks,
Avri

> 
> Kind regards
> Uffe

Re: [PATCH v2 0/2] mmc: core: Extend manufacturing date beyond 2025

[Ulf Hansson]

On Mon, 15 Dec 2025 at 17:28, Avri Altman <Avri.Altman@sandisk.com> wrote:
>
> > I have applied the series for next, thanks!
> >
> > However, I noticed that the author of the patch has your gmail-address and the
> > sob has your sandisk-address. I guess we should change to your sandisk-address
> > to be in both places, no?
> Yes. Sorry for missing this.

No worries, I have amended the commits accordingly.

Kind regards
Uffe