On 04/08/2013 02:48 PM, Shawn Guo wrote:
On Mon, Apr 08, 2013 at 12:12:20PM +0200, Hector Palacios wrote:
MicroSD card sockets don't usually have card detect line. This pin
is actually not needed for the MMC to work and it is more of a
platform design decission to have it.
The card detect pin already has a configuration entry of its own:
'mmc0_cd_cfg' so we complete the iomux configuration here and let
platforms to include it or not depending on whether the card detect
line is routed to the SD socket.

Sounds sensible.

Signed-off-by: Hector Palacios <hector.palac...@digi.com>
---

Hello,

All imx28 based platforms except 'bluegiga,apx4devkit' and
'schulercontrol,imx28-sps1', use 'mmc0_cd_cfg' in their mmc configuration
so please check whether this patch would break these platforms.

I just tested the patch on imx28-evk and card-detection still works.  So
patches applied, thanks.

The EVK and most platforms will work because they are using 'mmc0_cd_cfg' so actually this patch does not change anything on them. Platforms 'bluegiga,apx4devkit' and 'schulercontrol,imx28-sps1' however are not referencing 'mmc0_cd_cfg' so after applying this patch they will have unconfigured CD line and they may break.
The driver will call get_cd() upon probing, which returns the status of the CD 
line.
Please check these two platforms before applying.

In fact I was looking now at how to skip the calling of get_cd() hook when you specify 'non-removable' in the Device Tree. According to the bindings document:

  - non-removable: non-removable slot (like eMMC); *assume always present.*

This property is not handled in mxs-mmc.c but even if I add the code to handle it and set MMC_CAP_NONREMOVABLE flag, the get_cd() is called at least once and returning with the status of CD line. I think this is wrong because it should assume the card is present. The CD line may not be connected at all and may have any value.

Regards,
--
Héctor Palacios
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to