From: Wolfram Sang <wsa@the-dreams.de>
To: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Cc: linux-i2c@vger.kernel.org, anirudh@xilinx.com,
soren.brinkmann@xilinx.com, michal.simek@xilinx.com,
Shubhrajyoti Datta <shubhraj@xilinx.com>
Subject: Re: [PATCHv3 2/2] i2c: cadence: Implement save restore
Date: Thu, 3 Mar 2016 21:40:13 +0100 [thread overview]
Message-ID: <20160303204013.GC1711@katana> (raw)
In-Reply-To: <1456984240-17389-2-git-send-email-shubhraj@xilinx.com>
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On Thu, Mar 03, 2016 at 11:20:40AM +0530, Shubhrajyoti Datta wrote:
> Implement save restore for i2c module.
> Since we have only a couple of registers
> an unconditional restore is done.
But you only save one register instead of a couple? Also, the subject
could be more descriptive IMO.
> zynq-mp has the capability of going off.
> the current kernel does not hit off however some day it will.
> since the overhead of having the support is not much may be it is better to have it in the kernel.
This sounds like the patch is not tested?
> +static void cdns_i2c_init(struct cdns_i2c *id)
> +{
> + cdns_i2c_writereg(id->ctrl_reg, CDNS_I2C_CR_OFFSET);
> + /*
> + * Cadence I2C controller has a bug wherein it generates
> + * invalid read transaction after HW timeout in master receiver mode.
> + * HW timeout is not used by this driver and the interrupt is disabled.
> + * But the feature itself cannot be disabled. Hence maximum value
> + * is written to this register to reduce the chances of error.
> + */
> + cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET);
> +}
This...
> +
> +/**
> * cdns_i2c_runtime_resume - Runtime resume
> * @dev: Address of the platform_device structure
> *
> @@ -853,6 +874,7 @@ static int __maybe_unused cdns_i2c_runtime_resume(struct device *dev)
> dev_err(dev, "Cannot enable clock.\n");
> return ret;
> }
> + cdns_i2c_init(xi2c);
and this...
> -
> - /*
> - * Cadence I2C controller has a bug wherein it generates
> - * invalid read transaction after HW timeout in master receiver mode.
> - * HW timeout is not used by this driver and the interrupt is disabled.
> - * But the feature itself cannot be disabled. Hence maximum value
> - * is written to this register to reduce the chances of error.
> - */
> - cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET);
> + cdns_i2c_init(id);
... and this look like a unrelated change to me?
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next prev parent reply other threads:[~2016-03-03 20:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-03 5:50 [PATCHv3 1/2] i2c: cadence: Fix the Documentation Shubhrajyoti Datta
2016-03-03 5:50 ` [PATCHv3 2/2] i2c: cadence: Implement save restore Shubhrajyoti Datta
2016-03-03 20:40 ` Wolfram Sang [this message]
2016-03-04 4:25 ` Shubhrajyoti Datta
2016-03-12 15:02 ` Wolfram Sang
2016-03-12 17:23 ` Shubhrajyoti Datta
2016-03-03 20:33 ` [PATCHv3 1/2] i2c: cadence: Fix the Documentation Wolfram Sang
2016-03-04 4:52 ` Shubhrajyoti Datta
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