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authorHans de Goede <hdegoede@redhat.com>2015-04-01 18:26:23 +0300
committerUlf Hansson <ulf.hansson@linaro.org>2015-04-02 11:59:10 +0300
commit81f8a7be6642b4c26ab681b2e0f4c4120a6de1b0 (patch)
tree24868729a06b2b5fe678e7c9649c7e5a90cff9dc /drivers/mmc/core
parent2391b340ca5b7dd041a2bf86afe12bc004acb583 (diff)
downloadlinux-81f8a7be6642b4c26ab681b2e0f4c4120a6de1b0.tar.xz
mmc: Add support for marking hpi as broken through devicetree
The eMMC on a tablet I've will stop working / communicating as soon as the kernel executes: mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HPI_MGMT, 1, card->ext_csd.generic_cmd6_time); There seems to be no way to reliable identify eMMC-s which have a broken hpi implementation, but at least for eMMC's which are soldered onto a board we can work around this by specifying that hpi is broken in devicetree. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r--drivers/mmc/core/mmc.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 1d41e8541f38..c84131e28625 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -11,6 +11,7 @@
*/
#include <linux/err.h>
+#include <linux/of.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/pm_runtime.h>
@@ -336,6 +337,8 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
{
int err = 0, idx;
unsigned int part_size;
+ struct device_node *np;
+ bool broken_hpi = false;
/* Version is coded in the CSD_STRUCTURE byte in the EXT_CSD register */
card->ext_csd.raw_ext_csd_structure = ext_csd[EXT_CSD_STRUCTURE];
@@ -349,6 +352,11 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
}
}
+ np = mmc_of_find_child_device(card->host, 0);
+ if (np && of_device_is_compatible(np, "mmc-card"))
+ broken_hpi = of_property_read_bool(np, "broken-hpi");
+ of_node_put(np);
+
/*
* The EXT_CSD format is meant to be forward compatible. As long
* as CSD_STRUCTURE does not change, all values for EXT_CSD_REV
@@ -494,7 +502,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
}
/* check whether the eMMC card supports HPI */
- if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1) {
+ if (!broken_hpi && (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1)) {
card->ext_csd.hpi = 1;
if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x2)
card->ext_csd.hpi_cmd = MMC_STOP_TRANSMISSION;