Am 2016-11-14 10:37, schrieb Adrian Hunter:
On 14/11/16 10:50, Michael Walle wrote:
Am 2016-11-14 04:00, schrieb Y.B. Lu:
-----Original Message-----
From: Michael Walle [mailto:michael@xxxxxxxx]
Sent: Saturday, November 12, 2016 12:04 AM
To: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mmc@xxxxxxxxxxxxxxx; Ulf Hansson; Adrian Hunter; yangbo
lu;
Michael Walle
Subject: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read
Since commit 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect
busy
cards in __mmc_switch()") the ESDHC driver is broken:
mmc0: Card stuck in programming state! __mmc_switch
mmc0: error -110 whilst initialising MMC card
Since this commit __mmc_switch() uses ->card_busy(), which is
sdhci_card_busy() for the esdhc driver. sdhci_card_busy() uses the
PRESENT_STATE register, specifically the DAT0 signal level bit. But
the
ESDHC uses a non-conformant PRESENT_STATE register, thus a read
fixup is
required to make the driver work again.
Signed-off-by: Michael Walle <michael@xxxxxxxx>
Fixes: 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy
cards in
__mmc_switch()")
---
v2:
- use lower bits of the original value (that was actually a typo)
- add fixes tag
- fix typo
drivers/mmc/host/sdhci-of-esdhc.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c
b/drivers/mmc/host/sdhci-
of-esdhc.c
index fb71c86..f9c84bb 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -66,6 +66,18 @@ static u32 esdhc_readl_fixup(struct sdhci_host
*host,
return ret;
}
}
+ /*
+ * The DAT[3:0] line signal levels and the CMD line signal
level is
+ * not compatible with standard SDHC register. Move the
corresponding
+ * bits around.
+ */
+ if (spec_reg == SDHCI_PRESENT_STATE) {
+ ret = value & ~0xf8000000;
[Lu Yangbo-B47093] I think the bits which should be cleaned before
following '|=' are 0x01f00000 not 0xf8000000, right?
:)
Its neither 0x01f00000 nor 0xf8000000 :( I'll put the bits definition
into
the comment the next time, so everyone can review them. bit[31:24] are
the
line DAT[7:0] line signal level. bit[23] is command signal level. All
other
bits are the same as in the standard SDHC PRESENT_STATE register.
I want to keep all but the upper 9 bits from the original value,
therefore,
this should be the correct mask:
ret = value & ~0xff800000;
Why keep bits 22:20 ? Isn't it more logical to keep 19:0 (i.e. ret =
value
& 0xfffff)
These are 0 according to the datasheet but of course, it makes more
sense to mask these, too.
-michael
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