[U-Boot] eMMC issue with dcache ON

Siva Durga Prasad Paladugu siva.durga.paladugu at xilinx.com
Tue Dec 3 12:56:08 CET 2013


Hi all,

I am facing an issue in detecting eMMC device when the dcache was enabled on zynq board. When I entered command "mmcinfo". I am getting an error as shown in below log. The same thing works fine if I disable the dcache.

Timeout for status update!
Device: zynq_sdhci
Manufacturer ID: fe
OEM: 14e
Name: MMC04
Tran Speed: 25000000
Rd Block Len: 512
MMC version 4.41
High Capacity: Yes
Capacity: 3.6 GiB
Bus Width: 1-bit

When I debugged, I found that it was timing out, while sending command MMC_CMD_SWITCH from mmc_switch(). The same thing working fine if I just disable the cache before sending this command and enabling it after. The same thing also works fine for SD with dcache enabled
I tried by making the below changes but nothing worked.
1. Added data synchronization barrier in arch/arm/include/asm/io.h by thinking that that sdhci is using sdhci_readl/writel functions which has no barriers.
2. Enabled the config CONFIG_MMC_SDMA.

Please suggest what else could be done to solve this issue.



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