[PATCH v1 7/7] mci: imx-esdhc: support DMA in the i.MX8M PBL eMMC loader

[Sascha Hauer]

On 2026-06-27 19:43, Johannes Schneider wrote:
> The PBL eMMC loader was hardwired to PIO via esdhc_use_pio_mode(): IN_PBL
> forced PIO unconditionally. PIO is slow -- on an i.MX8MM board loading the
> ~1.6 MB next stage took ~559 ms; SDMA/ADMA2 do it in ~21 ms.

For proper DMA support you'll need memory synchronization in form of dma_map_*
or dma_sync_* helpers which we do not have in PBL. Without them it won't
work with MMU enabled. Have you tried enabling the MMU in the mean time? This
should give you decent performance even with PIO.

Sascha

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