Commit 16b90dd9 authored by Gustavo Pimentel's avatar Gustavo Pimentel Committed by Vinod Koul
Browse files

dmaengine: dw-edma: Improve number of channels check 



It was added some extra checks to ensure that the driver doesn't try to
use more DMA channels than actually are available in hardware.

Signed-off-by: default avatarGustavo Pimentel <gustavo.pimentel@synopsys.com>
Link: https://lore.kernel.org/r/cfb2b0a4f97ae9dc83ebe5ea59d6a51d69ea3654.1613674948.git.gustavo.pimentel@synopsys.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 85e7518f

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

+9 −12
Original line number Diff line number Diff line
@@ -914,19 +914,16 @@ int dw_edma_probe(struct dw_edma_chip *chip) 


	raw_spin_lock_init(&dw->lock);



	if (!dw->wr_ch_cnt) {

		/* Find out how many write channels are supported by hardware */

		dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE);

		if (!dw->wr_ch_cnt)

			return -EINVAL;

	}

	dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt,

			      dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE));

	dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt, EDMA_MAX_WR_CH);



	if (!dw->rd_ch_cnt) {

		/* Find out how many read channels are supported by hardware */

		dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ);

		if (!dw->rd_ch_cnt)

	dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt,

			      dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ));

	dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt, EDMA_MAX_RD_CH);



	if (!dw->wr_ch_cnt && !dw->rd_ch_cnt)

		return -EINVAL;

	}



	dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n",

		 dw->wr_ch_cnt, dw->rd_ch_cnt);

drivers/dma/dw-edma/dw-edma-core.h

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
#include "../virt-dma.h"



#define EDMA_LL_SZ					24

#define EDMA_MAX_WR_CH					8

#define EDMA_MAX_RD_CH					8



enum dw_edma_dir {

	EDMA_DIR_WRITE = 0,