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Subject[RFC PATCH 1/2] Revert "spi: atmel: fix corrupted data issue on SAM9 family SoCs"
Date
This reverts commit 7094576ccdc3acfe1e06a1e2ab547add375baf7f.

A better fix was found and DMA for SAM9 SoCs must be enabled.

Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
---
drivers/spi/spi-atmel.c | 24 +-----------------------
1 file changed, 1 insertion(+), 23 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index f95da36..4e5e51f 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -269,7 +269,6 @@ struct atmel_spi_caps {
bool is_spi2;
bool has_wdrbt;
bool has_dma_support;
- bool has_pdc_support;
};

/*
@@ -1426,28 +1425,7 @@ static void atmel_get_caps(struct atmel_spi *as)

as->caps.is_spi2 = version > 0x121;
as->caps.has_wdrbt = version >= 0x210;
-#ifdef CONFIG_SOC_SAM_V4_V5
- /*
- * Atmel SoCs based on ARM9 (SAM9x) cores should not use spi_map_buf()
- * since this later function tries to map buffers with dma_map_sg()
- * even if they have not been allocated inside DMA-safe areas.
- * On SoCs based on Cortex A5 (SAMA5Dx), it works anyway because for
- * those ARM cores, the data cache follows the PIPT model.
- * Also the L2 cache controller of SAMA5D2 uses the PIPT model too.
- * In case of PIPT caches, there cannot be cache aliases.
- * However on ARM9 cores, the data cache follows the VIVT model, hence
- * the cache aliases issue can occur when buffers are allocated from
- * DMA-unsafe areas, by vmalloc() for instance, where cache coherency is
- * not taken into account or at least not handled completely (cache
- * lines of aliases are not invalidated).
- * This is not a theorical issue: it was reproduced when trying to mount
- * a UBI file-system on a at91sam9g35ek board.
- */
- as->caps.has_dma_support = false;
-#else
as->caps.has_dma_support = version >= 0x212;
-#endif
- as->caps.has_pdc_support = version < 0x212;
}

/*-------------------------------------------------------------------------*/
@@ -1588,7 +1566,7 @@ static int atmel_spi_probe(struct platform_device *pdev)
} else if (ret == -EPROBE_DEFER) {
return ret;
}
- } else if (as->caps.has_pdc_support) {
+ } else {
as->use_pdc = true;
}

--
2.7.4
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