From: Ian Dannapel <iansdannapel@gmail.com>
To: linux@rempel-privat.de
Cc: kernel@pengutronix.de, shawnguo@kernel.org,
s.hauer@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com,
linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Michael.Glembotzki@iris-sensing.com,
Erik.Schumacher@iris-sensing.com,
Ian Dannapel <iansdannapel@gmail.com>
Subject: [PATCH] i2c: imx: remove unnecessary delay at startup
Date: Mon, 14 Mar 2022 10:59:18 +0100 [thread overview]
Message-ID: <20220314095918.50014-1-iansdannapel@gmail.com> (raw)
a delay on the startup of the i2c imx controller is not required or defined in the specs.
By removing it, the user can see a latency decrease from up to 150μs in communication.
Additional info: https://lore.kernel.org/all/20220304132037.GA15901@pengutronix.de/
Signed-off-by: Ian S. Dannapel <iansdannapel@gmail.com>
---
drivers/i2c/busses/i2c-imx.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 3576b63a6c03..019dda5301df 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -602,12 +602,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
- /* Wait controller to be stable */
- if (atomic)
- udelay(50);
- else
- usleep_range(50, 150);
-
/* Start I2C transaction */
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp |= I2CR_MSTA;
--
2.25.1
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next reply other threads:[~2022-03-14 10:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-14 9:59 Ian Dannapel [this message]
2022-03-14 10:13 ` [PATCH] i2c: imx: remove unnecessary delay at startup Uwe Kleine-König
2022-03-15 5:59 ` Oleksij Rempel
2022-03-15 7:44 ` Wolfram Sang
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