The atmel-mci driver sometimes fails data transfers like this:
   mmcblk0: error -5 transferring data

   end_request: I/O error, dev mmcblk0, sector 2749769

   end_request: I/O error, dev mmcblk0, sector 2749777
It turns out that this might be caused by the BLKR register (which

contains the block size and the number of blocks being transfered) being

initialized too late. This patch moves the initialization of BLKR so

that it contains the correct value before the block transfer command is

sent.
This error is difficult to reproduce, but if you insert a long delay

(mdelay(10) or thereabouts) between the calls to atmci_start_command()

and atmci_submit_data(), all transfers seem to fail without this patch,

while I haven't seen any failures with this patch.
Reported-by: Hein_Tibosch <hein_tibosch@yahoo.es>

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

---

 drivers/mmc/host/atmel-mci.c |    6 ++++--

 1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c

index 917035e..0000896 100644

--- a/drivers/mmc/host/atmel-mci.c

+++ b/drivers/mmc/host/atmel-mci.c

@@ -426,8 +426,6 @@ static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data)

 	host->sg = NULL;

 	host->data = data;
-	mci_writel(host, BLKR, MCI_BCNT(data->blocks)

-			| MCI_BLKLEN(data->blksz));

 	dev_vdbg(&mmc->class_dev, "BLKR=0x%08x\n",

 			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
@@ -483,6 +481,10 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)

 		if (data->blocks > 1 && data->blksz & 3)

 			goto fail;

 		atmci_set_timeout(host, data);

+

+		/* Must set block count/size before sending command */

+		mci_writel(host, BLKR, MCI_BCNT(data->blocks)

+				| MCI_BLKLEN(data->blksz));

 	}
 	iflags = MCI_CMDRDY;

--

1.5.6.5
--

Linus, any chance of getting this into .27? It has been seen in the

wild and causes I/O errors (which can lead to data loss).
If so, you can add:
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
On Fri,  3 Oct 2008 17:07:38 +0200
--=20

     -- Pierre Ossman
  Linux kernel, MMC maintainer        http://www.kernel.org

  rdesktop, core developer          http://www.rdesktop.org
  WARNING: This correspondence is being monitored by the

  Swedish government. Make sure your server uses encryption

  for SMTP traffic and consider using PGP for end-to-end

  encryption.

Please just send the whole patch. I don't want to have to go searching for

it somewhere else, or edit it for whitespace and quoting damage from you

quoting it. Just add
	From: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
at the top of the body to make attribution come out right (even though you

send it to me), and add your own Signed-off-by: at the end. That way I

have many fewer chances of screwing up, when I don't have to try to follow

the references list back to another mailbox or off to some archive site

(since I filter kernel mailing list email to another mailbox that I don't

archive and that I age aggressively to keep it recent and relevant).
		Linus

--

From: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
The atmel-mci driver sometimes fails data transfers like this:
   mmcblk0: error -5 transferring data

   end_request: I/O error, dev mmcblk0, sector 2749769

   end_request: I/O error, dev mmcblk0, sector 2749777
It turns out that this might be caused by the BLKR register (which

contains the block size and the number of blocks being transfered) being

initialized too late. This patch moves the initialization of BLKR so

that it contains the correct value before the block transfer command is

sent.
This error is difficult to reproduce, but if you insert a long delay

(mdelay(10) or thereabouts) between the calls to atmci_start_command()

and atmci_submit_data(), all transfers seem to fail without this patch,

while I haven't seen any failures with this patch.
Reported-by: Hein_Tibosch <hein_tibosch@yahoo.es>

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

---

 drivers/mmc/host/atmel-mci.c |    6 ++++--

 1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c

index 917035e..0000896 100644

--- a/drivers/mmc/host/atmel-mci.c

+++ b/drivers/mmc/host/atmel-mci.c

@@ -426,8 +426,6 @@ static u32 atmci_submit_data(struct mmc_host *mmc, stru=

ct mmc_data *data)

 	host->sg =3D NULL;

 	host->data =3D data;

=20

-	mci_writel(host, BLKR, MCI_BCNT(data->blocks)

-			| MCI_BLKLEN(data->blksz));

 	dev_vdbg(&mmc->class_dev, "BLKR=3D0x%08x\n",

 			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));

=20

@@ -483,6 +481,10 @@ static void atmci_request(struct mmc_host *mmc, struct=

 mmc_request *mrq)

 		if (data->blocks > 1 && data->blksz & 3)

 			goto fail;

 		atmci_set_timeout(host, data);

+

+		/* Must set block count/size before sending command */

+		mci_writel(host, BLKR, MCI_BCNT(data->blocks)

+				| MCI_BLKLEN(data->blksz));

 	}

...
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