SDIO firmware download error

[Jonathan Cameron]

On 03/30/10 21:29, Dan Williams wrote:
> On Thu, 2010-03-11 at 13:49 +0530, Alagu Sankar wrote:
>> Trying my luck with a different subject as the previous one was rejected..
>>
>> I am in the process of adding SDIO Support for Davinci and using the
>> Libertas SDIO driver as my standard test setup.  I am using the Linux
>> 2.6.33-rc6 Linux kernel and the associated libertas driver. I have
>> access to 8385, 8686 and 8688 cards from different vendors, with
>> diferent firmware versions. I would like to get some inputs from the
>> list for the following issue that I am facing.
>>
>> When I use the libertas driver as is, the helper download is always
>> successful, but the primary firmware loading fails after the first
>> transfer.  I get a req_size of 17 after the initial 16 byte transfer,
>> indicating that the error bit is set. For a typical working setup,
>> there is a 16 byte transfer, followed by a 12 byte transfer and so on.
>>  If I introduce a delay of 2 milli-seconds between each transfer of
>> the helper firmware, then there is no problem in downloading the
>> primary firmware.  Even enabling the debug message
>> "lbs_deb_sdio("sending %d bytes chunk\n", chunk_size);" alone would
>> result in successful firmware download.
> 
> If we can reproduce this issue on some other platform (to determine that
> the host controller is *not* the culprit) I'm not necessarily opposed to
> adding a small delay during helper firmware download in the driver.  But
> beyond adding some debugging prints to the MMC layer to conclusively
> determine that the HC is responding correctly or incorrectly to the
> transfers, I'm not really sure.  Are you aware of any errata for your
> SDIO controller that might affect this?
A similar problem exists on a pxa271.  I'm carrying the following patch
for it...  Note this is against a fairly old kernel, 2.6.32-rc6

Symptoms were exactly the same though.  There was a previous thread on this
list about it:

sdio 8686 firmware load problem

back on the 11th of August last year. 
---
Subject: [PATCH 01/10] Libertas_sdio: A timing issue during helper firmware loading was leading to a failure of the main firmware load on Imote2.

This patch adds an a 1 millisecond delay allowing successful
firmware load.

Signed-off-by: Jonathan Cameron <jic23 at cam.ac.uk>
---
 drivers/net/wireless/libertas/if_sdio.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
index 485a8d4..8a4e82c 100644
--- a/drivers/net/wireless/libertas/if_sdio.c
+++ b/drivers/net/wireless/libertas/if_sdio.c
@@ -514,6 +514,7 @@ static int if_sdio_prog_helper(struct if_sdio_card *card)
 /*
 		lbs_deb_sdio("sending %d bytes chunk\n", chunk_size);
 */
+		mdelay(1);
 		ret = sdio_writesb(card->func, card->ioport,
 				chunk_buffer, 64);
 		if (ret)
-- 
1.6.3.3