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| author | Paul Walmsley <paul@pwsan.com> | 2011-10-06 14:50:33 -0600 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2011-10-27 09:10:57 -0400 |
| commit | 2bf22b39823c1d173dda31111a4eb2ce36daaf39 (patch) | |
| tree | 54575fedfd2b032c3113b55dea5e2fd5d0c7eb38 /include | |
| parent | b6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a (diff) | |
| download | lwn-2bf22b39823c1d173dda31111a4eb2ce36daaf39.tar.gz lwn-2bf22b39823c1d173dda31111a4eb2ce36daaf39.zip | |
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.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 16e9338944e8..a3ac9c48e5de 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; |