+ravi On 8/23/21 11:41 PM, Marek Vasut wrote: > Booting ZynqMP with XIIC I2C driver shows multitude of race conditions > in the XIIC driver. This is because locking is completely missing from > the driver, and there are odd corner cases where the hardware behaves > strangely. > > Most of these races could be triggered easily when booting on SMP > machines, like the ZynqMP which has up to 4 cores. It is sufficient > for the interrupt handler to run on another core than xiic_start_xfer > and the driver fails completely. > > This does not add support for long transfers, this only fixes the > driver to be usable at all instead of being completely broken. > > The V2 fixes a few remaining details which cropped up in deployment > over the last year or so, so I believe the result should be reasonably > well tested. > > Marek Vasut (6): > i2c: xiic: Fix broken locking on tx_msg > i2c: xiic: Drop broken interrupt handler > i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in > xiic_process() > i2c: xiic: Switch from waitqueue to completion > i2c: xiic: Only ever transfer single message > i2c: xiic: Fix RX IRQ busy check > > drivers/i2c/busses/i2c-xiic.c | 161 +++++++++++++++------------------- > 1 file changed, 69 insertions(+), 92 deletions(-) > > Cc: Michal Simek <michal.simek@xxxxxxxxxx> > Cc: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx> > Cc: Wolfram Sang <wsa@xxxxxxxxxx> >
