Commit 6f4722b1 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Vinod Koul
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dmaengine: dw-edma: fix endianess confusion 

When building with 'make C=1', sparse reports an endianess bug:

drivers/dma/dw-edma/dw-edma-v0-debugfs.c:60:30: warning: cast removes address space of expression
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24: warning: incorrect type in argument 1 (different address spaces)
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24:    expected void const volatile [noderef] <asn:2>*addr
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24:    got void *[assigned] ptr
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24: warning: incorrect type in argument 1 (different address spaces)
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24:    expected void const volatile [noderef] <asn:2>*addr
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24:    got void *[assigned] ptr
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24: warning: incorrect type in argument 1 (different address spaces)
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24:    expected void const volatile [noderef] <asn:2>*addr
drivers/dma/dw-edma/dw-edma-v0-debugfs.c:86:24:    got void *[assigned] ptr

The current code is clearly wrong, as it passes an endian-swapped word
into a register function where it gets swapped again. Just pass the variables
directly into lower_32_bits()/upper_32_bits().

Fixes: 7e4b8a4f ("dmaengine: Add Synopsys eDMA IP version 0 support")
Link: https://lore.kernel.org/lkml/20190617131820.2470686-1-arnd@arndb.de/


Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarGustavo Pimentel <gustavo.pimentel@synopsys.com>
Link: https://lore.kernel.org/r/20190722124457.1093886-3-arnd@arndb.de


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 756c3ef9

drivers/dma/dw-edma/dw-edma-v0-core.c

+10 −14
Original line number Diff line number Diff line
@@ -195,7 +195,6 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk) 
	struct dw_edma_v0_lli __iomem *lli;

	struct dw_edma_v0_llp __iomem *llp;

	u32 control = 0, i = 0;

	u64 sar, dar, addr;

	int j;



	lli = chunk->ll_region.vaddr;
@@ -214,13 +213,11 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk) 
		/* Transfer size */

		SET_LL(&lli[i].transfer_size, child->sz);

		/* SAR - low, high */

		sar = cpu_to_le64(child->sar);

		SET_LL(&lli[i].sar_low, lower_32_bits(sar));

		SET_LL(&lli[i].sar_high, upper_32_bits(sar));

		SET_LL(&lli[i].sar_low, lower_32_bits(child->sar));

		SET_LL(&lli[i].sar_high, upper_32_bits(child->sar));

		/* DAR - low, high */

		dar = cpu_to_le64(child->dar);

		SET_LL(&lli[i].dar_low, lower_32_bits(dar));

		SET_LL(&lli[i].dar_high, upper_32_bits(dar));

		SET_LL(&lli[i].dar_low, lower_32_bits(child->dar));

		SET_LL(&lli[i].dar_high, upper_32_bits(child->dar));

		i++;

	}
@@ -232,9 +229,8 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk) 
	/* Channel control */

	SET_LL(&llp->control, control);

	/* Linked list  - low, high */

	addr = cpu_to_le64(chunk->ll_region.paddr);

	SET_LL(&llp->llp_low, lower_32_bits(addr));

	SET_LL(&llp->llp_high, upper_32_bits(addr));

	SET_LL(&llp->llp_low, lower_32_bits(chunk->ll_region.paddr));

	SET_LL(&llp->llp_high, upper_32_bits(chunk->ll_region.paddr));

}



void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
@@ -242,7 +238,6 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first) 
	struct dw_edma_chan *chan = chunk->chan;

	struct dw_edma *dw = chan->chip->dw;

	u32 tmp;

	u64 llp;



	dw_edma_v0_core_write_chunk(chunk);
@@ -262,9 +257,10 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first) 
		SET_CH(dw, chan->dir, chan->id, ch_control1,

		       (DW_EDMA_V0_CCS | DW_EDMA_V0_LLE));

		/* Linked list - low, high */

		llp = cpu_to_le64(chunk->ll_region.paddr);

		SET_CH(dw, chan->dir, chan->id, llp_low, lower_32_bits(llp));

		SET_CH(dw, chan->dir, chan->id, llp_high, upper_32_bits(llp));

		SET_CH(dw, chan->dir, chan->id, llp_low,

		       lower_32_bits(chunk->ll_region.paddr));

		SET_CH(dw, chan->dir, chan->id, llp_high,

		       upper_32_bits(chunk->ll_region.paddr));

	}

	/* Doorbell */

	SET_RW(dw, chan->dir, doorbell,

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