summaryrefslogtreecommitdiff
path: root/drivers/mmc
diff options
context:
space:
mode:
authorPierre Ossman <drzeus@drzeus.cx>2007-12-02 19:45:19 +0100
committerPierre Ossman <drzeus@drzeus.cx>2007-12-12 20:01:00 +0100
commitdc93441b3f5879a096dd117a81df541b0855ebbb (patch)
treede8e7c3391d0f9522622498d0d27517a722ed251 /drivers/mmc
parent75b8c133267053c9986a7c8db5131f0e7349e806 (diff)
sdhci: describe quirks
Add a comment for each quirk to describe what it does and why. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index ff59d2e0475b..17b4e391db35 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -26,12 +26,22 @@
static unsigned int debug_quirks = 0;
+/*
+ * Different quirks to handle when the hardware deviates from a strict
+ * interpretation of the SDHCI specification.
+ */
+
+/* Controller doesn't honor resets unless we touch the clock register */
#define SDHCI_QUIRK_CLOCK_BEFORE_RESET (1<<0)
+/* Controller has bad caps bits, but really supports DMA */
#define SDHCI_QUIRK_FORCE_DMA (1<<1)
/* Controller doesn't like some resets when there is no card inserted. */
#define SDHCI_QUIRK_NO_CARD_NO_RESET (1<<2)
+/* Controller doesn't like clearing the power reg before a change */
#define SDHCI_QUIRK_SINGLE_POWER_WRITE (1<<3)
+/* Controller has flaky internal state so reset it on each ios change */
#define SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS (1<<4)
+/* Controller has an unusable DMA engine */
#define SDHCI_QUIRK_BROKEN_DMA (1<<5)
static const struct pci_device_id pci_ids[] __devinitdata = {