Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7d2eadc9 authored by Jean-Francois Moine's avatar Jean-Francois Moine Committed by Russell King
Browse files

drm/i2c: tda998x: check more I/O errors 



This patch adds more error checking inn I2C I/O functions.
In case of I/O error, this permits to avoid writing in bad controller
pages, a bad chipset detection or looping when getting the EDID.

Tested-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarJean-Francois Moine <moinejf@free.fr>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 2f7f730a

drivers/gpu/drm/i2c/tda998x_drv.c

+43 −14
Original line number Diff line number Diff line
@@ -363,7 +363,7 @@ fail: 
	return 0;

}



static void

static int

set_page(struct tda998x_priv *priv, uint16_t reg)

{

	if (REG2PAGE(reg) != priv->current_page) {
@@ -372,11 +372,14 @@ set_page(struct tda998x_priv *priv, uint16_t reg) 
				REG_CURPAGE, REG2PAGE(reg)

		};

		int ret = i2c_master_send(client, buf, sizeof(buf));

		if (ret < 0)

		if (ret < 0) {

			dev_err(&client->dev, "Error %d writing to REG_CURPAGE\n", ret);

			return ret;

		}



		priv->current_page = REG2PAGE(reg);

	}

	return 0;

}



static int
@@ -386,7 +389,9 @@ reg_read_range(struct tda998x_priv *priv, uint16_t reg, char *buf, int cnt) 
	uint8_t addr = REG2ADDR(reg);

	int ret;



	set_page(priv, reg);

	ret = set_page(priv, reg);

	if (ret < 0)

		return ret;



	ret = i2c_master_send(client, &addr, sizeof(addr));

	if (ret < 0)
@@ -413,18 +418,24 @@ reg_write_range(struct tda998x_priv *priv, uint16_t reg, uint8_t *p, int cnt) 
	buf[0] = REG2ADDR(reg);

	memcpy(&buf[1], p, cnt);



	set_page(priv, reg);

	ret = set_page(priv, reg);

	if (ret < 0)

		return;



	ret = i2c_master_send(client, buf, cnt + 1);

	if (ret < 0)

		dev_err(&client->dev, "Error %d writing to 0x%x\n", ret, reg);

}



static uint8_t

static int

reg_read(struct tda998x_priv *priv, uint16_t reg)

{

	uint8_t val = 0;

	reg_read_range(priv, reg, &val, sizeof(val));

	int ret;



	ret = reg_read_range(priv, reg, &val, sizeof(val));

	if (ret < 0)

		return ret;

	return val;

}
@@ -435,7 +446,9 @@ reg_write(struct tda998x_priv *priv, uint16_t reg, uint8_t val) 
	uint8_t buf[] = {REG2ADDR(reg), val};

	int ret;



	set_page(priv, reg);

	ret = set_page(priv, reg);

	if (ret < 0)

		return;



	ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));

	if (ret < 0)
@@ -449,7 +462,9 @@ reg_write16(struct tda998x_priv *priv, uint16_t reg, uint16_t val) 
	uint8_t buf[] = {REG2ADDR(reg), val >> 8, val};

	int ret;



	set_page(priv, reg);

	ret = set_page(priv, reg);

	if (ret < 0)

		return;



	ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));

	if (ret < 0)
@@ -459,13 +474,21 @@ reg_write16(struct tda998x_priv *priv, uint16_t reg, uint16_t val) 
static void

reg_set(struct tda998x_priv *priv, uint16_t reg, uint8_t val)

{

	reg_write(priv, reg, reg_read(priv, reg) | val);

	int old_val;



	old_val = reg_read(priv, reg);

	if (old_val >= 0)

		reg_write(priv, reg, old_val | val);

}



static void

reg_clear(struct tda998x_priv *priv, uint16_t reg, uint8_t val)

{

	reg_write(priv, reg, reg_read(priv, reg) & ~val);

	int old_val;



	old_val = reg_read(priv, reg);

	if (old_val >= 0)

		reg_write(priv, reg, old_val & ~val);

}



static void
@@ -978,8 +1001,10 @@ read_edid_block(struct drm_encoder *encoder, uint8_t *buf, int blk) 


	/* wait for block read to complete: */

	for (i = 100; i > 0; i--) {

		uint8_t val = reg_read(priv, REG_INT_FLAGS_2);

		if (val & INT_FLAGS_2_EDID_BLK_RD)

		ret = reg_read(priv, REG_INT_FLAGS_2);

		if (ret < 0)

			return ret;

		if (ret & INT_FLAGS_2_EDID_BLK_RD)

			break;

		msleep(1);

	}
@@ -1144,6 +1169,7 @@ tda998x_encoder_init(struct i2c_client *client, 
		    struct drm_encoder_slave *encoder_slave)

{

	struct tda998x_priv *priv;

	int ret;



	priv = kzalloc(sizeof(*priv), GFP_KERNEL);

	if (!priv)
@@ -1172,8 +1198,11 @@ tda998x_encoder_init(struct i2c_client *client, 
	tda998x_reset(priv);



	/* read version: */

	priv->rev = reg_read(priv, REG_VERSION_LSB) |

			reg_read(priv, REG_VERSION_MSB) << 8;

	ret = reg_read(priv, REG_VERSION_LSB) |

		(reg_read(priv, REG_VERSION_MSB) << 8);

	if (ret < 0)

		goto fail;

	priv->rev = ret;



	/* mask off feature bits: */

	priv->rev &= ~0x30; /* not-hdcp and not-scalar bit */