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From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-i2c@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org,
	Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [PATCH 2/2] i2c: rcar: refactor and shorten timeout when resetting
Date: Sat, 29 Aug 2020 22:38:10 +0200	[thread overview]
Message-ID: <20200829203810.1467-3-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20200829203810.1467-1-wsa+renesas@sang-engineering.com>

LOOP_TIMEOUT was only used back then because we didn't want to introduce
another constant. The timeout value can easily be a magnitude shorter
because the typical range is 3us - 8us. Refactor the code to use the
poll_timeout helper, use a specific timeout value and get rid of the
ugly LOOP_TIMEOUT constant.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/busses/i2c-rcar.c | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index ef10514f6215..217def2d7cb4 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -150,9 +150,6 @@ struct rcar_i2c_priv {
 #define rcar_i2c_priv_to_dev(p)		((p)->adap.dev.parent)
 #define rcar_i2c_is_recv(p)		((p)->msg->flags & I2C_M_RD)
 
-#define LOOP_TIMEOUT	1024
-
-
 static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
 {
 	writel(val, priv->io + reg);
@@ -765,20 +762,14 @@ static void rcar_i2c_release_dma(struct rcar_i2c_priv *priv)
 /* I2C is a special case, we need to poll the status of a reset */
 static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv)
 {
-	int i, ret;
+	int ret;
 
 	ret = reset_control_reset(priv->rstc);
 	if (ret)
 		return ret;
 
-	for (i = 0; i < LOOP_TIMEOUT; i++) {
-		ret = reset_control_status(priv->rstc);
-		if (ret == 0)
-			return 0;
-		udelay(1);
-	}
-
-	return -ETIMEDOUT;
+	return read_poll_timeout_atomic(reset_control_status, ret, ret == 0, 1,
+					100, false, priv->rstc);
 }
 
 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
-- 
2.20.1


  parent reply	other threads:[~2020-08-29 20:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-29 20:38 [PATCH 0/2] i2c: rcar: use iopoll helpers for better timeout handling Wolfram Sang
2020-08-29 20:38 ` [PATCH 1/2] i2c: rcar: improve bus busy detection Wolfram Sang
2020-09-09  8:44   ` Wolfram Sang
2020-08-29 20:38 ` Wolfram Sang [this message]
2020-09-09  8:44   ` [PATCH 2/2] i2c: rcar: refactor and shorten timeout when resetting Wolfram Sang
2020-08-30  8:30 ` [PATCH 0/2] i2c: rcar: use iopoll helpers for better timeout handling Niklas Söderlund

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