From: Matthew Barth <msbarth@linux.ibm.com>
To: Eddie James <eajames@linux.ibm.com>, openbmc@lists.ozlabs.org
Cc: Andrew Jeffery <andrew@aj.id.au>
Subject: Re: [PATCH linux dev-5.10 06/14] pmbus: (max31785) Add a local pmbus_set_page() implementation
Date: Wed, 11 Aug 2021 11:13:32 -0500 [thread overview]
Message-ID: <d5b97b7a-5e64-1b66-4237-45b06ffe9524@linux.ibm.com> (raw)
In-Reply-To: <20210811154232.12649-7-eajames@linux.ibm.com>
On 8/11/21 10:42 AM, Eddie James wrote:
> From: Andrew Jeffery <andrew@aj.id.au>
>
> Extensive testing and tracing has shown that the MAX31785 is unreliable
> in the face of PAGE write commands, ACK'ing the PAGE request but
> reporting a value of 0 on some subsequent PAGE reads. The trace data
> suggests that a one-shot retry of the PAGE write is enough to get the
> requested value to stick.
>
> As we configure the device before registering with the PMBus core,
> centralise PAGE handling inside the driver and implement the one-shot
> retry semantics there.
>
> OpenBMC-Staging-Count: 1
> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Matthew Barth <msbarth@linux.ibm.com>
> ---
> drivers/hwmon/pmbus/max31785.c | 32 ++++++++++++++++++++++++++------
> 1 file changed, 26 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hwmon/pmbus/max31785.c b/drivers/hwmon/pmbus/max31785.c
> index d097f72d4d47..7518fff356f9 100644
> --- a/drivers/hwmon/pmbus/max31785.c
> +++ b/drivers/hwmon/pmbus/max31785.c
> @@ -362,6 +362,27 @@ static int max31785_write_word_data(struct i2c_client *client, int page,
> return -ENXIO;
> }
>
> +static int max31785_pmbus_set_page(struct i2c_client *client, int page)
> +{
> + int ret;
> + int i;
> +
> + for (i = 0; i < 2; i++) {
> + ret = max31785_i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
> + if (ret < 0)
> + return ret;
> +
> + ret = max31785_i2c_smbus_read_byte_data(client, PMBUS_PAGE);
> + if (ret < 0)
> + return ret;
> +
> + if (ret == page)
> + return 0;
> + }
> +
> + return -EIO;
> +}
> +
> /*
> * Returns negative error codes if an unrecoverable problem is detected, 0 if a
> * recoverable problem is detected, or a positive value on success.
> @@ -392,7 +413,7 @@ static int max31785_of_fan_config(struct i2c_client *client,
> return -ENXIO;
> }
>
> - ret = max31785_i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
> + ret = max31785_pmbus_set_page(client, page);
> if (ret < 0)
> return ret;
>
> @@ -599,7 +620,7 @@ static int max31785_of_tmp_config(struct i2c_client *client,
> return -ENXIO;
> }
>
> - ret = max31785_i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
> + ret = max31785_pmbus_set_page(client, page);
> if (ret < 0)
> return ret;
>
> @@ -700,7 +721,7 @@ static int max31785_configure_dual_tach(struct i2c_client *client,
> int i;
>
> for (i = 0; i < MAX31785_NR_FAN_PAGES; i++) {
> - ret = max31785_i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
> + ret = max31785_pmbus_set_page(client, i);
> if (ret < 0)
> return ret;
>
> @@ -741,7 +762,7 @@ static int max31785_probe(struct i2c_client *client)
>
> *info = max31785_info;
>
> - ret = max31785_i2c_smbus_write_byte_data(client, PMBUS_PAGE, 255);
> + ret = max31785_pmbus_set_page(client, 255);
> if (ret < 0)
> return ret;
>
> @@ -785,8 +806,7 @@ static int max31785_probe(struct i2c_client *client)
> if (!have_fan || fan_configured)
> continue;
>
> - ret = max31785_i2c_smbus_write_byte_data(client, PMBUS_PAGE,
> - i);
> + ret = max31785_pmbus_set_page(client, i);
> if (ret < 0)
> return ret;
>
next prev parent reply other threads:[~2021-08-11 16:42 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 15:42 [PATCH linux dev-5.10 00/14] Rainier and Everest system fixes Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 01/14] i2c: Allow throttling of transfers to client devices Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 02/14] pmbus: (ucd9000) Throttle SMBus transfers to avoid poor behaviour Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 03/14] ucd9000: Add a throttle delay attribute in debugfs Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 04/14] fsi: run clock at 100MHz Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 05/14] pmbus: (core) Add a one-shot retry in pmbus_set_page() Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 06/14] pmbus: (max31785) Add a local pmbus_set_page() implementation Eddie James
2021-08-11 16:13 ` Matthew Barth [this message]
2021-08-11 15:42 ` [PATCH linux dev-5.10 07/14] pmbus: (max31785) Retry enabling fans after writing MFR_FAN_CONFIG Eddie James
2021-08-11 16:14 ` Matthew Barth
2021-08-11 15:42 ` [PATCH linux dev-5.10 08/14] ARM: dts: aspeed: Rainier: Add fan controller properties Eddie James
2021-08-11 16:14 ` Matthew Barth
2021-08-11 15:42 ` [PATCH linux dev-5.10 09/14] ARM: dts: aspeed: Everest: " Eddie James
2021-08-11 16:15 ` Matthew Barth
2021-08-11 15:42 ` [PATCH linux dev-5.10 10/14] ARM: dts: aspeed: Rainier 4U: Delete fan dual-tach properties Eddie James
2021-08-11 16:17 ` Matthew Barth
2021-08-11 15:42 ` [PATCH linux dev-5.10 11/14] ARM: dts: aspeed: Add Rainier 2U and 4U device trees for pass 1 hardware Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 12/14] fsi: sbefifo: Increase command timeouts to 30 seconds Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 13/14] fsi: occ: Add dynamic debug to dump command and response Eddie James
2021-08-11 15:42 ` [PATCH linux dev-5.10 14/14] fsi: sbefifo: Use interruptible mutex locking Eddie James
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