[ep93xx] add 2.6.37 support

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@25535 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 74 insertions, 0 deletions

diff --git a/target/linux/ep93xx/patches-2.6.37/002-mmc_spi_fix_sdhc.patch b/target/linux/ep93xx/patches-2.6.37/002-mmc_spi_fix_sdhc.patch
new file mode 100644
index 0000000000..5211e00c49
--- /dev/null
+++ b/target/linux/ep93xx/patches-2.6.37/002-mmc_spi_fix_sdhc.patch
@@ -0,0 +1,74 @@
+This patch makes SDHC cards work with the mmc_spi driver.
+
+The problem is that they fail when reading the last block of the card using
+a multi-block read. This is because on SDHC the multiple block read has to be
+stopped with an explicit STOP command, which needs to be sent to the card
+while the incoming transfer is in progress.
+The 2.6.3[45] mmc-spi driver sends it after the last block transfer, so the
+SDHC card continues reading past the end of the card.
+This patch works around this by using single-block reads if we're reading the
+last blocks of the card.
+  -martinwguy, 14 May 2010
+
+Date: Thu, 29 Apr 2010 21:30:36 +0300
+From: Mika Westerberg <mika.westerberg@iki.fi>
+To: Martin Guy <martinwguy@gmail.com>
+
+On Wed, Apr 21, 2010 at 02:10:08AM +0100, Martin Guy wrote:
+> 
+> the SDHC cards I have don't work at all, spewing tons of:
+> mmcblk0: error -38 sending status comand
+> mmcblk0: error -38 sending read/write command, response 0x4, card status 0xff04
+> end_request: I/O error, dev mmcblk0, sector 7744509
+
+I bought today a new 4GB SDHC card and with that I get similar
+errors that you are getting. I hacked around quick fix which seems
+to work in my case. I'm wondering whether you could check if it
+helps with your SDHC card as well?
+
+This problem is easy to reproduce, just read last sector of the
+card (I wrote simple C program but running fdisk -l does the same).
+
+Patch is below.
+
+Thanks,
+MW
+
+From: Mika Westerberg <mika.westerberg@iki.fi>
+Date: Thu, 29 Apr 2010 21:14:32 +0300
+Subject: [PATCH] mmc_block: use single block reads for last block on SPI
+
+Some SD-cards fail when doing multiblock read for last block with SPI host. Real
+reason is not known but as workaround we can perform this last read using
+multiple single block reads.
+
+Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
+---
+ drivers/mmc/card/block.c |   19 +++++++++++++++++++
+ 1 files changed, 19 insertions(+), 0 deletions(-)
+
+--- a/drivers/mmc/card/block.c
++++ b/drivers/mmc/card/block.c
+@@ -366,6 +366,22 @@ static int mmc_blk_issue_rw_rq(struct mm
+ 		if (brq.data.blocks > card->host->max_blk_count)
+ 			brq.data.blocks = card->host->max_blk_count;
+ 
++		if (mmc_host_is_spi(card->host)) {
++			/*
++			 * Some SD-cards fail when we are reading last block
++			 * with multiblock read. In these cases we automatically
++			 * use single block reads. This only happens on SPI
++			 * hosts.
++			 */
++			if (rq_data_dir(req) == READ && brq.data.blocks > 1) {
++				sector_t s = blk_rq_pos(req) + brq.data.blocks;
++
++				if (s >= get_capacity(md->disk)) {
++					disable_multi = 1;
++				}
++			}
++		}
++
+ 		/*
+ 		 * After a read error, we redo the request one sector at a time
+ 		 * in order to accurately determine which sectors can be read