From: Tony Lindgren <tony@xxxxxxxxxxx> [ Upstream commit 34539b442b3bc7d5bf10164750302b60b91f18a7 ] The am335x devices started producing boot errors for resetting musb module in because of subtle timing changes: Unhandled fault: external abort on non-linefetch (0x1008) ... sysc_poll_reset_sysconfig from sysc_reset+0x109/0x12 sysc_reset from sysc_probe+0xa99/0xeb0 ... The fix is to flush posted write after enable before reset during probe. Note that some devices also need to specify the delay after enable with ti,sysc-delay-us, but this is not needed for musb on am335x based on my tests. Reported-by: kernelci.org bot <bot@xxxxxxxxxxxx> Closes: https://storage.kernelci.org/next/master/next-20230614/arm/multi_v7_defconfig+CONFIG_THUMB2_KERNEL=y/gcc-10/lab-cip/baseline-beaglebone-black.html Fixes: 596e7955692b ("bus: ti-sysc: Add support for software reset") Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/bus/ti-sysc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c index 7d508f9050038..71b541538801e 100644 --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -2089,6 +2089,8 @@ static int sysc_reset(struct sysc *ddata) sysc_val = sysc_read_sysconfig(ddata); sysc_val |= sysc_mask; sysc_write(ddata, sysc_offset, sysc_val); + /* Flush posted write */ + sysc_val = sysc_read_sysconfig(ddata); } if (ddata->cfg.srst_udelay) -- 2.40.1
