Hello, trying Linux 3.2.0-rc3 on an am1808 based board using MMCSD1 controller, and facing problems with using DMA. Deactivating use_dma=0 in the davinci_mmc controller and mmc works in pio mode without problems. So there are no hardware problems, pinmux is ok, psc are all on. Tried this on the AM1808 evalboard TMDXEXP1808L, and Linux 3.1 works with DMA without problems. Difference: On the AM1808 Evalboard TMDXEXP1808L MMCSD0 controller is used on my am1808 based board MMCSD1! Debugging in code and found, that on the am1808 evalboard I get on startup (first DMA access): CMD13, arg 0x00000000, R1/R5/R6/R7 response a status back in mmc_davinci_irq(): TRNDNE (0x1000) Transfer done RSPDNE (0x0004) Response succesfully has received DATDNE (0x0001) The data has been fully transmitted On the am1808 based board with using MMCSD1 I get: CMD13, arg 0x00000000, R1/R5/R6/R7 response TRNDNE (0x1000) Transfer done DRRDY (0x0400) MMCDRR is ready New data arrived and can be read by cpu or dma RSPDNE (0x0004) Response succesfully has received after that command, I see no more mmc accesses ... some ideas? Looking in the sprufu5.pdf (AM18x ARM Microprocessor Enhanced Direct Memory Access (EDMA3) Controller" chapter "2.6 Event, Channel, and PaRAM Mapping": "Most of the DMA channels are tied to a specific hardware peripheral event, thus allowing transfers to be triggered by events from device peripherals or external hardware." The mapping is defined in the device specific manual http://www.ti.com/lit/ds/sprs653b/sprs653b.pdf chapter "5.9.1 EDMA3 Channel Synchronization Events" and there I found: EDMA0 Controller Event 16 MMCSD0 Receive EDMA0 Controller Event 17 MMCSD0 Transmit EDMA1 Controller Event 28 MMCSD1 Receive EDMA1 Controller Event 29 MMCSD1 Transmit The Linux 3.1 Code is using EDMA1 Controller Event 28 MMCSD1 Receive EDMA1 Controller Event 29 MMCSD1 Transmit as events for the MMCSD1 controller ... so, this should be ok ... I see no more differences between MMCSD0 and MMCSD1 ... maybe I miss something? Have somebody running an am1808 based board with using MMCSD controller 1? bye, Heiko -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
