Commit ed5a8104 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang
Browse files

i2c: rcar: sanity check for minimal DMA length 



Use a macro for the hardcoded value and apply a build check. If it is
not met, the driver logic will not work anymore.

Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 0d735031

drivers/i2c/busses/i2c-rcar.c

+6 −2
Original line number Diff line number Diff line
@@ -85,6 +85,7 @@ 
/* ICFBSCR */

#define TCYC17	0x0f		/* 17*Tcyc delay 1st bit between SDA and SCL */



#define RCAR_MIN_DMA_LEN	8



#define RCAR_BUS_PHASE_START	(MDBS | MIE | ESG)

#define RCAR_BUS_PHASE_DATA	(MDBS | MIE)
@@ -412,8 +413,8 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv) 
	int len;



	/* Do various checks to see if DMA is feasible at all */

	if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE) ||

	    (read && priv->flags & ID_P_NO_RXDMA))

	if (IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||

	    !(msg->flags & I2C_M_DMA_SAFE) || (read && priv->flags & ID_P_NO_RXDMA))

		return;



	if (read) {
@@ -921,6 +922,9 @@ static int rcar_i2c_probe(struct platform_device *pdev) 
	struct i2c_timings i2c_t;

	int irq, ret;



	/* Otherwise logic will break because some bytes must always use PIO */

	BUILD_BUG_ON_MSG(RCAR_MIN_DMA_LEN < 3, "Invalid min DMA length");



	priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;

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