[Skiboot] [PATCH 1/2] ast-io: Use bmc_sio_{get, put}() where required

[Andrew Jeffery]

Booting the host with a particular BMC configuration could lead to the
following error appearing in the OPAL msglog:

	[   71.470748378,3] PLAT: AST IO initialisation failed!

Wrap access to BMC_SIO_PLAT_FLAGS in bmc_sio_get()/bmc_sio_put() in
order to unlock and relock the SuperIO controller as required and avoid
the failure.

Fixes: ebc8524a3a45 ("ast-io: Rework setup/tear-down of communication with the BMC")
Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
 hw/ast-bmc/ast-io.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/ast-bmc/ast-io.c b/hw/ast-bmc/ast-io.c
index 4277e2d10ec3..a6ae85a4d24f 100644
--- a/hw/ast-bmc/ast-io.c
+++ b/hw/ast-bmc/ast-io.c
@@ -407,7 +407,13 @@ bool ast_sio_disable(void)
 
 bool ast_can_isolate_sp(void)
 {
-	return bmc_sio_inb(BMC_SIO_PLAT_FLAGS) & BMC_SIO_PLAT_ISOLATE_SP;
+	bool isolate;
+
+	bmc_sio_get(BMC_SIO_DEV_LPC2AHB);
+	isolate = bmc_sio_inb(BMC_SIO_PLAT_FLAGS) & BMC_SIO_PLAT_ISOLATE_SP;
+	bmc_sio_put(true);
+
+	return isolate;
 }
 
 bool ast_io_is_rw(void)
-- 
2.17.1