Hi, there's a regression on Designware I2C controllers that do not implement the IC_ENABLE_STATUS register, as detailed in thread "[bug] some versions of designware i2c lack enable status register" at https://www.spinics.net/lists/linux-i2c/msg34009.html Unfortunately I did not hear anything back from Ben, not even regarding the IP core revision on his board. Looking on my own, I've found that there's a possible race with the interrupt handler that may be causing problems. Patch 1 adds missing IRQ synchronization, patch 2 reverts the commit that caused a regression, and patch 3 is a bonus refactoring, as I believe the low-level enable-disable functionality is now quite messy. Cc: Ben Gardner <gardner.ben@xxxxxxxxx> Cc: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx> Alexander Monakov (3): i2c: designware: avoid race with interrupt handler Revert "i2c: designware: must wait for enable" i2c: designware: refactor low-level enable/disable drivers/i2c/busses/i2c-designware-common.c | 20 +++++++++----------- drivers/i2c/busses/i2c-designware-core.h | 13 +++++++++++-- drivers/i2c/busses/i2c-designware-master.c | 10 ++++++---- drivers/i2c/busses/i2c-designware-slave.c | 6 +++--- 4 files changed, 29 insertions(+), 20 deletions(-) -- 2.11.0
