Messages in this thread | | | Subject | Re: [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma | From | Tudor Ambarus <> | Date | Fri, 25 May 2018 17:51:36 +0300 |
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Hi, Peter,
On 04/11/2018 06:34 PM, Nicolas Ferre wrote: > I'll try to move forward with your detailed explanation and with my > contacts within the "product" team internally.
We have talked with the hardware team, looks like there is an error in the description of the Master to Slave Access matrix. CPU accesses DDR2 port0 through AXI matrix and not AHB. There is no conflict between CPU and LCDC DMA when accessing DDR2 ports. This explains why using CPU helps.
The slave numbers from "Table 14-3 Master to Slave Access" are wrong. The 7th row should be removed and all the other rows from below it, shifted up with one level (DDR2 Port 1 is Slave no 7, DDR2 port 2 is Slave no 8, ... , APB1 is slave no 11).
We think the best way is to keep LCD on DDR Ports 2 and 3 (8th and 9th slaves), to have maximum bandwidth and to use DMA on DDR port 1 for NAND (7th slave).
Also, some information about your configuration is useful. Can you please tell us what NAND DMA configuration did you use? Are you using NAND storage for the videos that you are playing on the LCD screen?
Thanks, ta
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