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From: Yao Yuan <yao.yuan@freescale.com>
To: "fugang.duan@freescale.com" <fugang.duan@freescale.com>,
	"wsa@the-dreams.de" <wsa@the-dreams.de>,
	"marex@denx.de" <marex@denx.de>
Cc: "LW@KARO-electronics.de" <LW@KARO-electronics.de>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"shawn.guo@linaro.org" <shawn.guo@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
	"Frank.Li@freescale.com" <Frank.Li@freescale.com>
Subject: RE: [PATCH v6 1/2] i2c: imx: add DMA support for freescale i2c driver
Date: Thu, 7 Aug 2014 08:04:58 +0000	[thread overview]
Message-ID: <c9727eaf22dc40f796793c6b127dfb9e@BL2PR03MB338.namprd03.prod.outlook.com> (raw)
In-Reply-To: <31f8f5504fc24d999f5af74338602bed@BLUPR03MB373.namprd03.prod.outlook.com>

Hi Fugang,

> >> >+	/* Waiting for Transfer complete. */
> >> >+	while (timeout--) {
> >> >+		temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> >> >+		if (temp & I2SR_ICF)
> >> >+			break;
> >> >+		udelay(10);
> >> >+	}
> >> Whether there have better method like interrupt to avoid dead wait
> >> here until timeout ?
> >
> >Can you give me more suggestion? We have discussed it with our team, It
> >seems the short query wait is necessary.
> >
> At least, you can use schdule_timeout() instead of udelay() ?

In fact, the waiting time normally is less than 10-50us, but the minimum time interval for schdule_timeout() is 1 jiffies.
So maybe schdule_timeout() is not very necessary?




Thanks for your review.

Best Regards,
Yuan Yao

  reply	other threads:[~2014-08-07  8:05 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-05  9:56 [PATCH v6 0/2] " Yuan Yao
2014-08-05  9:56 ` [PATCH v6 1/2] " Yuan Yao
2014-08-05 11:48   ` Varka Bhadram
2014-08-06  2:26     ` Yao Yuan
2014-08-06  7:20       ` Wolfram Sang
2014-08-06  2:33   ` fugang.duan
2014-08-06  7:06     ` Yao Yuan
2014-08-07  5:28       ` fugang.duan
2014-08-07  8:04         ` Yao Yuan [this message]
2014-08-07 10:01           ` fugang.duan
2014-08-07 13:18             ` Lothar Waßmann
2014-08-05  9:56 ` [PATCH v6 2/2] Documentation:add " Yuan Yao

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