From: Tony Lindgren tony@atomide.com
[ 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@kernelci.org Closes: https://storage.kernelci.org/next/master/next-20230614/arm/multi_v7_defconfi... Fixes: 596e7955692b ("bus: ti-sysc: Add support for software reset") Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 21fe9854703f9..4cb23b9e06ea4 100644 --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -2142,6 +2142,8 @@ 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)