From: Philip Rakity <prakity@xxxxxxxxxxx>
max_current_caps can return 0 if not available from the sd controller.
if no regulator is present or the regulator specifies a current
less then 200ma we will set the 200ma caps bit by default.
do not do this.
Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
Reviewed-by: Aaron Lu <aaron_lu@xxxxxxx>
---
drivers/mmc/core/sd.c | 23 ++++++++++++-----------
drivers/mmc/host/sdhci.c | 2 +-
include/linux/mmc/card.h | 1 +
3 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index c272c68..c6fc3e8 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -553,13 +553,13 @@ static int sd_set_bus_speed_mode(struct mmc_card *card, u8 *status)
static int sd_set_current_limit(struct mmc_card *card, u8 *status)
{
- int current_limit = 0;
+ int current_limit = SD_SET_CURRENT_NO_CHANGE;
int err;
/*
* Current limit switch is only defined for SDR50, SDR104, and DDR50
- * bus speed modes. For other bus speed modes, we set the default
- * current limit of 200mA.
+ * bus speed modes. For other bus speed modes, we do not change the
+ * current limit.
*/
if ((card->sd_bus_speed == UHS_SDR50_BUS_SPEED) ||
(card->sd_bus_speed == UHS_SDR104_BUS_SPEED) ||
@@ -595,17 +595,18 @@ static int sd_set_current_limit(struct mmc_card *card, u8 *status)
if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_200)
current_limit = SD_SET_CURRENT_LIMIT_200;
}
- } else
- current_limit = SD_SET_CURRENT_LIMIT_200;
+ }
- err = mmc_sd_switch(card, 1, 3, current_limit, status);
- if (err)
- return err;
+ if (current_limit != SD_SET_CURRENT_NO_CHANGE) {
+ err = mmc_sd_switch(card, 1, 3, current_limit, status);
+ if (err)
+ return err;
- if (((status[15] >> 4) & 0x0F) != current_limit)
- pr_warning("%s: Problem setting current limit!\n",
- mmc_hostname(card->host));
+ if (((status[15] >> 4) & 0x0F) != current_limit)
+ pr_warning("%s: Problem setting current limit!\n",
+ mmc_hostname(card->host));
+ }
return 0;
}
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 22347d4..8d8dff0 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2914,7 +2914,7 @@ int sdhci_add_host(struct sdhci_host *host)
mmc->caps |= MMC_CAP_MAX_CURRENT_600;
else if (max_current_180 >= 400)
mmc->caps |= MMC_CAP_MAX_CURRENT_400;
- else
+ else if (max_current_180 >= 200)
mmc->caps |= MMC_CAP_MAX_CURRENT_200;
}
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 629b823..a999771 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -145,6 +145,7 @@ struct sd_switch_caps {
#define SD_SET_CURRENT_LIMIT_400 1
#define SD_SET_CURRENT_LIMIT_600 2
#define SD_SET_CURRENT_LIMIT_800 3
+#define SD_SET_CURRENT_NO_CHANGE (-1)
#define SD_MAX_CURRENT_200 (1 << SD_SET_CURRENT_LIMIT_200)
#define SD_MAX_CURRENT_400 (1 << SD_SET_CURRENT_LIMIT_400)
--
1.7.0.4
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