[PATCH v6 45/49] net/wan/fsl_ucc_hdlc: fix reading of __be16 registers

From: Rasmus Villemoes
Date: Thu Nov 28 2019 - 09:58:46 EST


When releasing the allocated muram resource, we rely on reading back
the offsets from the riptr/tiptr registers. But those registers are
__be16 (and we indeed write them using iowrite16be), so we can't just
read them back with a normal C dereference.

This is not currently a real problem, since for now the driver is
PPC32-only. But it will soon be allowed to be used on arm and arm64 as
well.

Reviewed-by: Timur Tabi <timur@xxxxxxxxxx>
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
drivers/net/wan/fsl_ucc_hdlc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index 405b24a5a60d..8d13586bb774 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -732,8 +732,8 @@ static int uhdlc_open(struct net_device *dev)

static void uhdlc_memclean(struct ucc_hdlc_private *priv)
{
- qe_muram_free(priv->ucc_pram->riptr);
- qe_muram_free(priv->ucc_pram->tiptr);
+ qe_muram_free(ioread16be(&priv->ucc_pram->riptr));
+ qe_muram_free(ioread16be(&priv->ucc_pram->tiptr));

if (priv->rx_bd_base) {
dma_free_coherent(priv->dev,
--
2.23.0