On 2018-10-20 19:23, Vinod wrote: > On 18-10-18, 13:57, Gustavo Pimentel wrote: >> >> >> On 18/10/2018 13:41, Andy Shevchenko wrote: >>> On Thu, Oct 18, 2018 at 11:50:24AM +0100, Gustavo Pimentel wrote: >>>> On 18/10/2018 09:02, Peter Ujfalusi wrote: >>>>> On 2018-10-17 14:42, Gustavo Pimentel wrote: >>>>> Fixed up the email addresses.. >>> >>>>>> I'm implementing a new DMA driver for an IP and I've used /drivers/dma/dw/* >>>>>> driver has reference. This driver uses DMA engine framework. >>>>>> >>>>>> Now I would like to start testing my new driver by using DMAtest tool, I've >>>>>> follow the instructions written on [1], but I don't get any output from it. >>>>>> I think DMAtest didn't even started... Can you help to track down this? >>> >>>>> Do you have support for DMA_MEM_TO_MEM and implementation for the >>>>> device_prep_dma_memcpy callback? >>> >>>>> If yes, then add debug to your device_prep_dma_memcpy first to see if it >>>>> goes well, then to your device_issue_pending and device_tx_status callbacks. >>> >>>> Unfortunately I don't have it. I only have support for DMA_DEV_TO_MEM and >>>> DMA_MEM_TO_DEV. >>> >>> You can't use dmatest for such engine. >>> >>> Hint: find an SPI or UART controller and do a loopback test with DMA enabled. >> >> Ok, thanks for the hint. > > The biggest issue with DMAtest not being able to use peripheral transfers > is the fact by nature these transfers are device dependent and one needs > special hardware (something which can generate data and feed to > peripheral and vice-versa) and we can "try" verifying. and for DEV_TO_MEM/MEM_TO_DEV we need hw trigger from the peripheral to pace the DMA. MEM_TO_MEM does not need hw signal to trigger. > So, right now DMAtest can only provide memcpy transfers and verification. In desperate times I used scope to verify the MEM_TO_DEV data by monitoring the clk and data lines, but I still needed a working driver for the peripheral. As I don't have signal generator I assumed that DEV_TO_MEM 'just works'... - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
