i.MX Processors中的主题 Re: Yocto i.mx28 eMMC Problem

Yocto i.mx28 eMMC Problem

contra — Thu, 28 May 2015 15:23:44 GMT

Hi,

We have a board which is based on the i.MX28 EVK design but with eMMC on SSP1.

We are using Yocto dora and have built the qte-in-use-image. The image works when programmed to SD card and booted from SSP0. When I program the eMMC with the same image (qte-in-use-image-imx28evk.sdcard) the result from the debug port at power on is 'HTLFLCM0x80206008'. The links are set correctly to boot from SSP1.

We previously used LTIB and this worked booted with no source changes except the kernel boot string. Can anyone help to understand the problem?

Re: Yocto i.mx28 eMMC Problem

alejandrolozan1 — Mon, 08 Jun 2015 17:17:13 GMT

Hi,

The error code is the next:

#define ERROR_SSP_DRIVER_DMA_TIMEOUT (ERROR_DDI_GROUP | ERROR_DDI_SSP_DRIVER_GROUP | 0x8)

0x80206008 DMA Timed out

After checking the documentation I believe this error corresponds to this description.

Data Time-Out Error—The SSP TIMEOUT counter is used to detect a time-out

condition during data write or read operations. The time-out counts any time that the

SSP is waiting on a busy DAT bus. For read operations, the DAT line(s) indicate

busy before the card sends the start bit. For write operations, the DAT line(s) may

indicate busy after the block has been sent to the card. If the time-out counter expires

before the DAT line(s) become ready, the SSP stops any DMA requests, sets the

DATA_TIMEOUT status flag, and asserts a CPU IRQ. The ISR should check the

status register to see that a data time-out has occurred. It can then reset the DMA

channel and the SSP to re-try the operation.

I have seen previous problems with different SD card brands. Each SD card or eMMC needs a different amount of time to access w/r its internal memory. And it seems that depending on the memory, the BootROM code may rise that error.

I wonder if you have tried with a different eMMC.

/Alejandro

Re: Yocto i.mx28 eMMC Problem

jimmychan — Tue, 09 Jun 2015 04:05:39 GMT

have you try only put bootloader in EMMC?

Re: Yocto i.mx28 eMMC Problem

contra — Thu, 11 Jun 2015 09:02:08 GMT

Yes I have tried running only the bootloader in EMMC. At the moment I am using only the u-boot from Yocto. It will boot from MMC0 but not MMC1. At the moment I don't think EMMC is the problem, I think that MMC1 is not being set up. Is there a patch to get MMC1 to work?