[PATCH] mci: core: clarify why write_bl_len is the same as read_bl_len

[Jules Maselbas]

Signed-off-by: Jules Maselbas <jmaselbas at zdiv.net>
---
 drivers/mci/mci-core.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index 5a8f81ecb8..0afb0d26c8 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -1070,8 +1070,12 @@ static void mci_extract_block_lengths_from_csd(struct mci *mci)
 {
 	mci->read_bl_len = 1 << UNSTUFF_BITS(mci->csd, 80, 4);
 
+	/* Quoting Physical Layer Simplified Specification Version 9.10:
+	 * Note that in an SD Memory Card the WRITE_BL_LEN is always
+	 * equal to READ_BL_LEN.
+	 */
 	if (IS_SD(mci))
-		mci->write_bl_len = mci->read_bl_len;	/* FIXME why? */
+		mci->write_bl_len = mci->read_bl_len;
 	else
 		mci->write_bl_len = 1 << ((mci->csd[3] >> 22) & 0xf);
 
-- 
2.45.0