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From: Mark Brown <broonie@kernel.org>
To: Quan Nguyen <quan@os.amperecomputing.com>
Cc: Joel Stanley <joel@jms.id.au>, Andrew Jeffery <andrew@aj.id.au>,
	Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Rob Herring <robh+dt@kernel.org>,
	Lee Jones <lee.jones@linaro.org>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Derek Kiernan <derek.kiernan@xilinx.com>,
	Dragan Cvetic <dragan.cvetic@xilinx.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>,
	Open Source Submission <patches@amperecomputing.com>,
	Phong Vo <phong@os.amperecomputing.com>,
	"Thang Q . Nguyen" <thang@os.amperecomputing.com>
Subject: Re: [PATCH v6 6/9] misc: smpro-errmon: Add Ampere's SMpro error monitor driver
Date: Fri, 24 Dec 2021 13:28:57 +0000	[thread overview]
Message-ID: <YcXLGYWx4gYq/Y+J@sirena.org.uk> (raw)
In-Reply-To: <20211224041352.29405-7-quan@os.amperecomputing.com>

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On Fri, Dec 24, 2021 at 11:13:49AM +0700, Quan Nguyen wrote:

> +static int read_i2c_block_data(struct i2c_client *client, u16 address, u16 length, u8 *data)
> +{
> +	unsigned char outbuf[MAX_READ_BLOCK_LENGTH];
> +	unsigned char inbuf[2];
> +	struct i2c_msg msgs[2];
> +	ssize_t ret;
> +
> +	inbuf[0] = (address & 0xff);
> +	inbuf[1] = length;
> +
> +	msgs[0].addr = client->addr;
> +	msgs[0].flags = client->flags & I2C_M_TEN;
> +	msgs[0].len = 2;
> +	msgs[0].buf = inbuf;
> +
> +	msgs[1].addr = client->addr;
> +	msgs[1].flags = (client->flags  & I2C_M_TEN) | I2C_M_RD;
> +	msgs[1].len = length;
> +	msgs[1].buf = outbuf;
> +
> +	ret = i2c_transfer(client->adapter, msgs, NUM_I2C_MESSAGES);
> +	if (ret < 0)

regmap already supports bulk data access so it's not clear why we
would open code this.  Given that this is a single I2C transfer
it's also unclear why we'd need to export the regmap lock - a
single I2C transfer is atomic at the bus level so the regmap lock
isn't providing any additional concurrency protection.

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WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org>
To: Quan Nguyen <quan@os.amperecomputing.com>
Cc: linux-aspeed@lists.ozlabs.org, linux-doc@vger.kernel.org,
	Dragan Cvetic <dragan.cvetic@xilinx.com>,
	Phong Vo <phong@os.amperecomputing.com>,
	Lee Jones <lee.jones@linaro.org>,
	Jonathan Corbet <corbet@lwn.net>,
	openbmc@lists.ozlabs.org,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Derek Kiernan <derek.kiernan@xilinx.com>,
	Guenter Roeck <linux@roeck-us.net>,
	devicetree@vger.kernel.org, Jean Delvare <jdelvare@suse.com>,
	Arnd Bergmann <arnd@arndb.de>,
	"Thang Q . Nguyen" <thang@os.amperecomputing.com>,
	Rob Herring <robh+dt@kernel.org>,
	Open Source Submission <patches@amperecomputing.com>,
	linux-hwmon@vger.kernel.org, Andrew Jeffery <andrew@aj.id.au>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org,
	Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>
Subject: Re: [PATCH v6 6/9] misc: smpro-errmon: Add Ampere's SMpro error monitor driver
Date: Fri, 24 Dec 2021 13:28:57 +0000	[thread overview]
Message-ID: <YcXLGYWx4gYq/Y+J@sirena.org.uk> (raw)
In-Reply-To: <20211224041352.29405-7-quan@os.amperecomputing.com>

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On Fri, Dec 24, 2021 at 11:13:49AM +0700, Quan Nguyen wrote:

> +static int read_i2c_block_data(struct i2c_client *client, u16 address, u16 length, u8 *data)
> +{
> +	unsigned char outbuf[MAX_READ_BLOCK_LENGTH];
> +	unsigned char inbuf[2];
> +	struct i2c_msg msgs[2];
> +	ssize_t ret;
> +
> +	inbuf[0] = (address & 0xff);
> +	inbuf[1] = length;
> +
> +	msgs[0].addr = client->addr;
> +	msgs[0].flags = client->flags & I2C_M_TEN;
> +	msgs[0].len = 2;
> +	msgs[0].buf = inbuf;
> +
> +	msgs[1].addr = client->addr;
> +	msgs[1].flags = (client->flags  & I2C_M_TEN) | I2C_M_RD;
> +	msgs[1].len = length;
> +	msgs[1].buf = outbuf;
> +
> +	ret = i2c_transfer(client->adapter, msgs, NUM_I2C_MESSAGES);
> +	if (ret < 0)

regmap already supports bulk data access so it's not clear why we
would open code this.  Given that this is a single I2C transfer
it's also unclear why we'd need to export the regmap lock - a
single I2C transfer is atomic at the bus level so the regmap lock
isn't providing any additional concurrency protection.

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  parent reply	other threads:[~2021-12-24 13:29 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-24  4:13 [PATCH v6 0/9] Add Ampere's Altra SMPro MFD and its child drivers Quan Nguyen
2021-12-24  4:13 ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 1/9] dt-bindings: mfd: Add bindings for Ampere Altra SMPro MFD driver Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 2/9] mfd: smpro-mfd: Adds Ampere's Altra SMpro " Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2022-02-08  9:12   ` Lee Jones
2022-02-08  9:12     ` Lee Jones
2022-03-07  8:31   ` Quan Nguyen
2022-03-07  8:31     ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 3/9] hwmon: smpro: Add Ampere's Altra smpro-hwmon driver Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 4/9] docs: hwmon: (smpro-hwmon) Add documentation Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 5/9] regmap: Introduces regmap lock helpers Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2021-12-24 13:19   ` Mark Brown
2021-12-24 13:19     ` Mark Brown
2022-03-07  8:31     ` Quan Nguyen
2022-03-07  8:31       ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 6/9] misc: smpro-errmon: Add Ampere's SMpro error monitor driver Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2021-12-24  8:32   ` Greg Kroah-Hartman
2021-12-24  8:32     ` Greg Kroah-Hartman
2022-03-07  8:32     ` Quan Nguyen
2022-03-07  8:32       ` Quan Nguyen
2021-12-24 13:28   ` Mark Brown [this message]
2021-12-24 13:28     ` Mark Brown
2022-03-07  8:30     ` Quan Nguyen
2022-03-07  8:30       ` Quan Nguyen
2021-12-28  6:31   ` kernel test robot
2021-12-29 10:16   ` Lee Jones
2021-12-29 10:16     ` Lee Jones
2022-03-07  8:31   ` Quan Nguyen
2022-03-07  8:31     ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 7/9] docs: misc-devices: (smpro-errmon) Add documentation Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2021-12-24  4:13 ` [PATCH v6 8/9] misc: smpro-misc: Add Ampere's Altra SMpro misc driver Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen
2021-12-29 10:18   ` Lee Jones
2021-12-29 10:18     ` Lee Jones
2022-03-07  8:32   ` Quan Nguyen
2022-03-07  8:32     ` Quan Nguyen
2022-03-07 13:16     ` Arnd Bergmann
2022-03-07 13:16       ` Arnd Bergmann
2021-12-24  4:13 ` [PATCH v6 9/9] docs: misc-devices: (smpro-misc) Add documentation Quan Nguyen
2021-12-24  4:13   ` Quan Nguyen

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