Am Wed, 11 Sep 2024 11:40:04 +0200 schrieb "H. Nikolaus Schaller" <hns@xxxxxxxxxxxxx>: > Hi, > > > Am 28.04.2023 um 20:30 schrieb Reid Tonking <reidt@xxxxxx>: > > > > On 10:43-20230428, Tony Lindgren wrote: > >> * Raghavendra, Vignesh <vigneshr@xxxxxx> [230427 13:18]: > >>> On 4/27/2023 1:19 AM, Reid Tonking wrote: > >>>> Using standard mode, rare false ACK responses were appearing with > >>>> i2cdetect tool. This was happening due to NACK interrupt > >>>> triggering ISR thread before register access interrupt was > >>>> ready. Removing the NACK interrupt's ability to trigger ISR > >>>> thread lets register access ready interrupt do this instead. > >> > >> So is it safe to leave NACK interrupt unhandled until we get the > >> next interrupt, does the ARDY always trigger after hitting this? > >> > >> Regards, > >> > >> Tony > > > > Yep, the ARDY always gets set after a new command when register > > access is ready so there's no need for NACK interrupt to control > > this. > > I have tested one GTA04A5 board where this patch breaks boot on > v4.19.283 or v6.11-rc7 (where it was inherited from some earlier -rc > series). > > The device is either stuck with no signs of activity or reports RCU > stalls after a 20 second pause. > Reproduced some problem here: i2cset 1 0x69 0x14 0xb6 (reset command for gyro BMG160) [ 736.136108] omap_i2c 48072000.i2c: addr: 0x0069, len: 2, flags: 0x0, stop: 1 [ 736.136322] omap_i2c 48072000.i2c: IRQ (ISR = 0x0010) either with this patch applied: ... system mostly hangs, i2cset does not return. with it reverted: ... most times I see after this: [ 736.136505] omap_i2c 48072000.i2c: IRQ (ISR = 0x0002) and i2cset says: i2cset: write failed: Remote I/O error ... sometimes: omap_i2c 48072000.i2c: IRQ (ISR = 0x0004) and i2cset is successful. Other register writes seem to work reliably, just the reset command. I had tested with bmg driver disabled earlier, so it did not come to light. Regards, Andreas
