[PATCH 5.19 079/155] mmc: core: Fix inconsistent sd3_bus_mode at UHS-I SD voltage switch failure

Greg Kroah-Hartman
2022-09-06T14:11:02Z

From: Adrian Hunter <adrian.hunter@intel.com>

commit 63f1560930e4e1c4f6279b8ae715c9841fe1a6d3 upstream.

If re-initialization results is a different signal voltage, because the
voltage switch failed previously, but not this time (or vice versa), then
sd3_bus_mode will be inconsistent with the card because the SD_SWITCH
command is done only upon first initialization.

Fix by always reading SD_SWITCH information during re-initialization, which
also means it does not need to be re-read later for the 1.8V fixup
workaround.

Note, brief testing showed SD_SWITCH took about 1.8ms to 2ms which added
about 1% to 1.5% to the re-initialization time, so it's not particularly
significant.

Reported-by: Seunghui Lee <sh043.lee@samsung.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Seunghui Lee <sh043.lee@samsung.com>
Tested-by: Seunghui Lee <sh043.lee@samsung.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220815073321.63382-3-adrian.hunter@intel.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mmc/core/sd.c | 42 ++++++++++++++++--------------------------
1 file changed, 16 insertions(+), 26 deletions(-)

--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -949,16 +949,17 @@ int mmc_sd_setup_card(struct mmc_host *h

/* Erase init depends on CSD and SSR */
mmc_init_erase(card);
-
- /*
- * Fetch switch information from card.
- */
- err = mmc_read_switch(card);
- if (err)
- return err;
}

/*
+ * Fetch switch information from card. Note, sd3_bus_mode can change if
+ * voltage switch outcome changes, so do this always.
+ */
+ err = mmc_read_switch(card);
+ if (err)
+ return err;
+
+ /*
* For SPI, enable CRC as appropriate.
* This CRC enable is located AFTER the reading of the
* card registers because some SDHC cards are not able
@@ -1480,26 +1481,15 @@ retry:
if (!v18_fixup_failed && !mmc_host_is_spi(host) && mmc_host_uhs(host) &&
mmc_sd_card_using_v18(card) &&
host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
- /*
- * Re-read switch information in case it has changed since
- * oldcard was initialized.
- */
- if (oldcard) {
- err = mmc_read_switch(card);
- if (err)
- goto free_card;
- }
- if (mmc_sd_card_using_v18(card)) {
- if (mmc_host_set_uhs_voltage(host) ||
- mmc_sd_init_uhs_card(card)) {
- v18_fixup_failed = true;
- mmc_power_cycle(host, ocr);
- if (!oldcard)
- mmc_remove_card(card);
- goto retry;
- }
- goto cont;
+ if (mmc_host_set_uhs_voltage(host) ||
+ mmc_sd_init_uhs_card(card)) {
+ v18_fixup_failed = true;
+ mmc_power_cycle(host, ocr);
+ if (!oldcard)
+ mmc_remove_card(card);
+ goto retry;
}
+ goto cont;
}

/* Initialization sequence for UHS-I cards */