mmc: sdhci: add quirk for max len ADMA descriptors
Some controllers misparse segment length 0 as being 0, not 65536. Add
a quirk to deal with it.
Signed-off-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index d5febe5..9e15f41 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1949,10 +1949,14 @@
* of bytes. When doing hardware scatter/gather, each entry cannot
* be larger than 64 KiB though.
*/
- if (host->flags & SDHCI_USE_ADMA)
- mmc->max_seg_size = 65536;
- else
+ if (host->flags & SDHCI_USE_ADMA) {
+ if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC)
+ mmc->max_seg_size = 65535;
+ else
+ mmc->max_seg_size = 65536;
+ } else {
mmc->max_seg_size = mmc->max_req_size;
+ }
/*
* Maximum block size. This varies from controller to controller and
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index 0d953f5..83bd9f7 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -83,6 +83,8 @@
#define SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12 (1<<28)
/* Controller doesn't have HISPD bit field in HI-SPEED SD card */
#define SDHCI_QUIRK_NO_HISPD_BIT (1<<29)
+/* Controller treats ADMA descriptors with length 0000h incorrectly */
+#define SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC (1<<30)
int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */
