STM platforms use the sdhci-pltfm.c driver but, IMO
there are some problems when use the eMMC card.
--- from sdhci.c file:
1897 if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) &&
1898 mmc_card_is_removable(mmc))
1899 mmc->caps |= MMC_CAP_NEEDS_POLL;
[snip]
sdhci_set_card_detection
|_ if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
return;
sdhci_request
|_ /* If polling, assume that the card is always present. */
---
Passing the SDHCI_QUIRK_BROKEN_CARD_DETECTION as quirk
from my platform, IIUC, that guarantees that the card is actually
considered always present by the HC but the MMC_CAP_NONREMOVABLE is not set.
In fact some sdhci drivers based, to manage eMMC, actually do:
if (pdata-><own_field> == <OWN_PLATF>_PERMANET) {
host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
host->mmc->caps = MMC_CAP_NONREMOVABLE;
}
I need to do the same in the sdhci-pltfm for properly and logically use the
eMMC.
Moreover setting the SDHCI_QUIRK_BROKEN_CARD_DETECTION quirk
if we have a board with an eMMC (really plugged on) we skip,
in the sdhci_set_card_detection, the check of the card.
This works but it's logically broken and could create problems
on a board that has no eMMC soldered on the PCB yet.
Hmm, this is a limit case indeed. :-) but somebody followed in
this problem asking support for.
So a new quirk, called SDHCI_QUIRK_NONREMOVABLE_CARD, has been added.
This can be passed from the platform and managed in the sdhci to
directly set MMC_CAP_NONREMOVABLE.
To summarise:
o The meaning of SDHCI_QUIRK_BROKEN_CARD_DETECTION is:
Card detection is broken but if there is a removal card
(MMC_CAP_NEEDS_POLL is set) the sdhci considers it
present. If there is an eMMC do not needs poll and
the HC consider it as present too (really bad HW).
o The SDHCI_QUIRK_NONREMOVABLE_CARD meaning is:
we have the eMMC and set the MMC_CAP_NONREMOVABLE caps
and the sdhci has to verify if it is present otherwise
can fail.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
---
drivers/mmc/host/sdhci.c | 3 +++
include/linux/mmc/sdhci.h | 2 ++
2 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 9e15f41..650ea97 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1894,6 +1894,9 @@ int sdhci_add_host(struct sdhci_host *host)
if (caps & SDHCI_CAN_DO_HISPD)
mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
+ if (host->quirks & SDHCI_QUIRK_NONREMOVABLE_CARD)
+ mmc->caps |= MMC_CAP_NONREMOVABLE;
+
if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) &&
mmc_card_is_removable(mmc))
mmc->caps |= MMC_CAP_NEEDS_POLL;
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index 83bd9f7..370258c 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -85,6 +85,8 @@ struct sdhci_host {
#define SDHCI_QUIRK_NO_HISPD_BIT (1<<29)
/* Controller treats ADMA descriptors with length 0000h incorrectly */
#define SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC (1<<30)
+/* Controller has to treat an eMMC card */
+#define SDHCI_QUIRK_NONREMOVABLE_CARD (1<<31)
int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */
--
1.7.4.4
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