[PATCH] bus: ti-sysc: Fix external abort for am335x pruss probe

From: Tony Lindgren
Date: Wed Sep 15 2021 - 02:50:43 EST


Starting with v5.15-rc1, I'm now seeing am335x beaglebone black produce
the following error on pruss probe:

Unhandled fault: external abort on non-linefetch (0x1008) at 0xe0326000

This seems to have started with the enabling of pruss for am335x in the
dts files. Adding a read-back after write to the sysconfig register fixes
the issue for me.

Cc: Suman Anna <s-anna@xxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/bus/ti-sysc.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -2037,6 +2037,9 @@ 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_read_sysconfig(ddata);
}

if (ddata->cfg.srst_udelay)
--
2.33.0