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path: root/drivers/mmc/core/sdio.c
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Diffstat (limited to 'drivers/mmc/core/sdio.c')
-rw-r--r--drivers/mmc/core/sdio.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index f417adc9feb1..6810b3a8e130 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -633,7 +633,11 @@ try_again:
* to switch to 1.8V signaling level. No 1.8v signalling if
* UHS mode is not enabled to maintain compatibility and some
* systems that claim 1.8v signalling in fact do not support
- * it.
+ * it. Per SDIO spec v3, section 3.1.2, if the voltage is already
+ * 1.8v, the card sets S18A to 0 in the R4 response. So it will
+ * fails to check rocr & R4_18V_PRESENT, but we still need to
+ * try to init uhs card. sdio_read_cccr will take over this task
+ * to make sure which speed mode should work.
*/
if (!powered_resume && (rocr & ocr & R4_18V_PRESENT)) {
err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
@@ -645,9 +649,6 @@ try_again:
} else if (err) {
ocr &= ~R4_18V_PRESENT;
}
- err = 0;
- } else {
- ocr &= ~R4_18V_PRESENT;
}
/*
@@ -704,11 +705,20 @@ try_again:
}
/*
- * Read the common registers.
+ * Read the common registers. Note that we should try to
+ * validate whether UHS would work or not.
*/
err = sdio_read_cccr(card, ocr);
- if (err)
- goto remove;
+ if (err) {
+ mmc_sdio_resend_if_cond(host, card);
+ if (ocr & R4_18V_PRESENT) {
+ /* Retry init sequence, but without R4_18V_PRESENT. */
+ retries = 0;
+ goto try_again;
+ } else {
+ goto remove;
+ }
+ }
/*
* Read the common CIS tuples.