From: Eddie James <eajames@linux.ibm.com>
To: openbmc@lists.ozlabs.org
Cc: Andrew Jeffery <andrew@aj.id.au>
Subject: [PATCH linux dev-5.10 02/14] pmbus: (ucd9000) Throttle SMBus transfers to avoid poor behaviour
Date: Wed, 11 Aug 2021 10:42:20 -0500 [thread overview]
Message-ID: <20210811154232.12649-3-eajames@linux.ibm.com> (raw)
In-Reply-To: <20210811154232.12649-1-eajames@linux.ibm.com>
From: Andrew Jeffery <andrew@aj.id.au>
Short turn-around times between transfers to UCD9000 devices can lead to
problematic behaviour, including unnecessary clock stretching, bus
lockups and potential corruption of the device's volatile state.
Introduce transfer throttling for the device with a minimum access
delay of 1ms.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
drivers/hwmon/pmbus/ucd9000.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
index a15e6fe3e425..9687bc3609d1 100644
--- a/drivers/hwmon/pmbus/ucd9000.c
+++ b/drivers/hwmon/pmbus/ucd9000.c
@@ -487,6 +487,8 @@ static int ucd9000_init_debugfs(struct i2c_client *client,
}
#endif /* CONFIG_DEBUG_FS */
+#define UCD9000_SMBUS_THROTTLE_US 1000
+
static int ucd9000_probe(struct i2c_client *client)
{
u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
@@ -501,6 +503,8 @@ static int ucd9000_probe(struct i2c_client *client)
I2C_FUNC_SMBUS_BLOCK_DATA))
return -ENODEV;
+ i2c_smbus_throttle_client(client, UCD9000_SMBUS_THROTTLE_US);
+
ret = i2c_smbus_read_block_data(client, UCD9000_DEVICE_ID,
block_buffer);
if (ret < 0) {
--
2.27.0
next prev parent reply other threads:[~2021-08-11 15:49 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 ` Eddie James [this message]
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
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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