From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-i2c@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, Keerthy <j-keerthy@ti.com>,
Peter Rosin <peda@axentia.se>, Tony Lindgren <tony@atomide.com>,
Russell King <linux@armlinux.org.uk>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Stefan Lengfeld <contact@stefanchrist.eu>,
Phil Reid <preid@electromag.com.au>,
Tero Kristo <t-kristo@ti.com>,
linux-omap@vger.kernel.org, linux-tegra@vger.kernel.org,
Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [RFC PATCH v2 2/7] i2c: core: use I2C locking behaviour also for SMBUS
Date: Sat, 2 Mar 2019 14:47:30 +0100 [thread overview]
Message-ID: <20190302134735.4393-3-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20190302134735.4393-1-wsa+renesas@sang-engineering.com>
If I2C transfers are executed in atomic contexts, trylock is used
instead of lock. This behaviour was missing for SMBUS, although a lot of
transfers are of SMBUS type, either emulated or direct. So, factor out
the locking routine into a helper and use it for I2C and SMBUS.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Tony Lindgren <tony@atomide.com>
---
drivers/i2c/i2c-core-base.c | 11 +++--------
drivers/i2c/i2c-core-smbus.c | 7 ++++++-
drivers/i2c/i2c-core.h | 12 ++++++++++++
3 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index cb6c5cb0df0b..004f8a3b6365 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1946,14 +1946,9 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
* one (discarding status on the second message) or errno
* (discarding status on the first one).
*/
- if (in_atomic() || irqs_disabled()) {
- ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
- if (!ret)
- /* I2C activity is ongoing. */
- return -EAGAIN;
- } else {
- i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
- }
+ ret = __i2c_lock_bus_helper(adap);
+ if (ret)
+ return ret;
ret = __i2c_transfer(adap, msgs, num);
i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index 132119112596..357e083e8f45 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -20,6 +20,8 @@
#include <linux/i2c-smbus.h>
#include <linux/slab.h>
+#include "i2c-core.h"
+
#define CREATE_TRACE_POINTS
#include <trace/events/smbus.h>
@@ -530,7 +532,10 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
{
s32 res;
- i2c_lock_bus(adapter, I2C_LOCK_SEGMENT);
+ res = __i2c_lock_bus_helper(adapter);
+ if (res)
+ return res;
+
res = __i2c_smbus_xfer(adapter, addr, flags, read_write,
command, protocol, data);
i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT);
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 37576f50fe20..6e98aa811980 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -29,6 +29,18 @@ extern int __i2c_first_dynamic_bus_num;
int i2c_check_7bit_addr_validity_strict(unsigned short addr);
+static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
+{
+ int ret = 0;
+
+ if (in_atomic() || irqs_disabled())
+ ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
+ else
+ i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
+
+ return ret;
+}
+
#ifdef CONFIG_ACPI
const struct acpi_device_id *
i2c_acpi_match_device(const struct acpi_device_id *matches,
--
2.11.0
next prev parent reply other threads:[~2019-03-02 13:48 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-02 13:47 [RFC PATCH v2 0/7] i2c: core: introduce atomic transfers Wolfram Sang
2019-03-02 13:47 ` [RFC PATCH v2 1/7] i2c: apply coding style for struct i2c_adapter Wolfram Sang
2019-03-15 12:15 ` Simon Horman
2019-03-27 13:15 ` Wolfram Sang
2019-03-02 13:47 ` Wolfram Sang [this message]
2019-03-04 12:35 ` [RFC PATCH v2 2/7] i2c: core: use I2C locking behaviour also for SMBUS Geert Uytterhoeven
2019-03-15 12:17 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 3/7] i2c: core: introduce callbacks for atomic transfers Wolfram Sang
2019-03-15 12:23 ` Simon Horman
2019-03-27 13:47 ` Wolfram Sang
2019-03-29 9:45 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 4/7] i2c: demux: WIP: handle the new atomic callbacks Wolfram Sang
2019-03-15 12:32 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 5/7] i2c: busses: omap: Add the master_xfer_irqless hook Wolfram Sang
2019-03-15 12:47 ` Simon Horman
2019-03-15 13:14 ` Andy Shevchenko
2019-03-27 13:50 ` Wolfram Sang
2019-03-29 9:45 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 6/7] i2c: tegra-bpmp: convert to use new atomic callbacks Wolfram Sang
2019-03-04 12:25 ` Timo Alho
2019-03-04 12:59 ` Thierry Reding
2019-03-15 12:42 ` Simon Horman
2019-03-26 20:20 ` Stefan Lengfeld
2019-03-27 13:51 ` Wolfram Sang
2019-03-02 13:47 ` [RFC PATCH v2 7/7] i2c: algo: bit: HACK! add atomic callback Wolfram Sang
2019-03-02 16:22 ` [RFC PATCH v2 0/7] i2c: core: introduce atomic transfers Andy Shevchenko
2019-03-12 15:45 ` Wolfram Sang
2019-03-25 13:40 ` Wolfram Sang
2019-03-04 18:11 ` Peter Rosin
2019-03-04 22:48 ` Wolfram Sang
2019-03-07 0:02 ` Peter Rosin
2019-03-27 13:53 ` Wolfram Sang
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