5.4-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Bara benjamin.bara@skidata.com
commit a3368e1186e3ce8e38f78cbca019622095b1f331 upstream.
Since commit aa49c90894d0 ("i2c: core: Run atomic i2c xfer when !preemptible"), the whole reboot/power off sequence on non-preempt kernels is using atomic i2c xfer, as !preemptible() always results to 1.
During device_shutdown(), the i2c might be used a lot and not all busses have implemented an atomic xfer handler. This results in a lot of avoidable noise, like:
[ 12.687169] No atomic I2C transfer handler for 'i2c-0' [ 12.692313] WARNING: CPU: 6 PID: 275 at drivers/i2c/i2c-core.h:40 i2c_smbus_xfer+0x100/0x118 ...
Fix this by allowing non-atomic xfer when the interrupts are enabled, as it was before.
Link: https://lore.kernel.org/r/20231222230106.73f030a5@yea Link: https://lore.kernel.org/r/20240102150350.3180741-1-mwalle@kernel.org Link: https://lore.kernel.org/linux-i2c/13271b9b-4132-46ef-abf8-2c311967bb46@mailb... Fixes: aa49c90894d0 ("i2c: core: Run atomic i2c xfer when !preemptible") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Benjamin Bara benjamin.bara@skidata.com Tested-by: Michael Walle mwalle@kernel.org Tested-by: Tor Vic torvic9@mailbox.org [wsa: removed a comment which needs more work, code is ok] Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/i2c/i2c-core.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -3,6 +3,7 @@ * i2c-core.h - interfaces internal to the I2C framework */
+#include <linux/kconfig.h> #include <linux/rwsem.h>
struct i2c_devinfo { @@ -29,7 +30,8 @@ int i2c_dev_irq_from_resources(const str */ static inline bool i2c_in_atomic_xfer_mode(void) { - return system_state > SYSTEM_RUNNING && !preemptible(); + return system_state > SYSTEM_RUNNING && + (IS_ENABLED(CONFIG_PREEMPT_COUNT) ? !preemptible() : irqs_disabled()); }
static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)