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authorPaul Walmsley <paul@pwsan.com>2011-10-06 14:50:33 -0600
committerChris Ball <cjb@laptop.org>2011-10-27 09:10:57 -0400
commit2bf22b39823c1d173dda31111a4eb2ce36daaf39 (patch)
tree54575fedfd2b032c3113b55dea5e2fd5d0c7eb38 /include
parentb6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a (diff)
mmc: core: add workaround for controllers with broken multiblock reads
Due to hardware bugs, some MMC host controllers don't support multiple-block reads[1]. To resolve, add a new MMC capability flag, MMC_CAP2_NO_MULTI_READ, which can be set by affected host controller drivers. When this capability is set, all reads will be issued one sector at a time. 1. See for example Advisory 2.1.1.128 "MMC: Multiple Block Read Operation Issue" in _OMAP3530/3525/3515/3503 Silicon Errata_ Revision F (October 2010) (SPRZ278F), available from http://focus.ti.com/lit/er/sprz278f/sprz278f.pdf Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Dave Hylands <dhylands@gmail.com> Tested-by: Steve Sakoman <sakoman@gmail.com> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/mmc/host.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 16e9338944e..a3ac9c48e5d 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -241,6 +241,7 @@ struct mmc_host {
#define MMC_CAP2_BOOTPART_NOACC (1 << 0) /* Boot partition no access */
#define MMC_CAP2_CACHE_CTRL (1 << 1) /* Allow cache control */
#define MMC_CAP2_POWEROFF_NOTIFY (1 << 2) /* Notify poweroff supported */
+#define MMC_CAP2_NO_MULTI_READ (1 << 3) /* Multiblock reads don't work */
mmc_pm_flag_t pm_caps; /* supported pm features */
unsigned int power_notify_type;