[PATCH 5/7] mmc_spi: allow higher timeouts for SPI mode

From: Wolfgang Mües
Date: Wed Mar 11 2009 - 09:29:05 EST


From: Wolfgang Muees <wolfgang.mues@xxxxxxxxxxxx>

o Some SD cards have very high timeouts in SPI mode.
So adjust the timeouts from theory to practice.

Signed-off-by: Wolfgang Muees <wolfgang.mues@xxxxxxxxxxxx>

---
This is one of a line of patches to enhance the usability of
the mmc spi host port driver from "don't work with most SD cards"
to "work with nearly all SD cards" (including those ugly cards
with non-byte-aligned responses).

diff -uprN 2_6_29_rc7_patch4_no_crc_on_CID_CSD/drivers/mmc/core/core.c 2_6_29_rc7_patch5_extra_spi_timeouts/drivers/mmc/core/core.c
--- 2_6_29_rc7_patch4_no_crc_on_CID_CSD/drivers/mmc/core/core.c 2009-03-04 02:05:22.000000000 +0100
+++ 2_6_29_rc7_patch5_extra_spi_timeouts/drivers/mmc/core/core.c 2009-03-10 12:06:16.000000000 +0100
@@ -297,6 +297,21 @@ void mmc_set_data_timeout(struct mmc_dat
data->timeout_clks = 0;
}
}
+ /*
+ * Some cards need very high timeouts if driven in SPI mode.
+ * The worst observed timeout was 900ms after writing a
+ * continuous stream of data until the internal logic
+ * overflowed.
+ */
+ if (mmc_host_is_spi(card->host)) {
+ if (data->flags & MMC_DATA_WRITE) {
+ if (data->timeout_ns < 1000000000)
+ data->timeout_ns = 1000000000; /* 1s */
+ } else {
+ if (data->timeout_ns < 100000000)
+ data->timeout_ns = 100000000; /* 100ms */
+ }
+ }
}
EXPORT_SYMBOL(mmc_set_data_timeout);

---
regards

i. A. Wolfgang Mües
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