Re: [PATCH v3 -next 4/4] net: emaclite: Fix restricted cast warning of sparse
From: Andrew Lunn <andrew@lunn.ch>
Date: 2020-01-31 13:48:54
Also in:
linux-arm-kernel, lkml
On Fri, Jan 31, 2020 at 05:17:50PM +0530, Radhey Shyam Pandey wrote:
quoted hunk ↗ jump to hunk
Explicitly cast xemaclite_readl return value when it's passed to ntohl. Fixes below reported sparse warnings: xilinx_emaclite.c:411:24: sparse: sparse: cast to restricted __be32 xilinx_emaclite.c:420:36: sparse: sparse: cast to restricted __be32 Signed-off-by: Radhey Shyam Pandey <redacted> Reported-by: kbuild test robot <redacted> --- drivers/net/ethernet/xilinx/xilinx_emaclite.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c b/drivers/net/ethernet/xilinx/xilinx_emaclite.c index 96e9d21..3273d4f 100644 --- a/drivers/net/ethernet/xilinx/xilinx_emaclite.c +++ b/drivers/net/ethernet/xilinx/xilinx_emaclite.c@@ -408,7 +408,8 @@ static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data, int maxlen) /* Get the protocol type of the ethernet frame that arrived */ - proto_type = ((ntohl(xemaclite_readl(addr + XEL_HEADER_OFFSET + + proto_type = ((ntohl((__force __be32)xemaclite_readl(addr + + XEL_HEADER_OFFSET + XEL_RXBUFF_OFFSET)) >> XEL_HEADER_SHIFT) & XEL_RPLR_LENGTH_MASK);@@ -417,7 +418,7 @@ static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data, int maxlen) */ if (proto_type > ETH_DATA_LEN) { if (proto_type == ETH_P_IP) { - length = ((ntohl(xemaclite_readl(addr + + length = ((ntohl((__force __be32)xemaclite_readl(addr + XEL_HEADER_IP_LENGTH_OFFSET + XEL_RXBUFF_OFFSET)) >> XEL_HEADER_SHIFT) &
If i understand this code correctly, you need the ntohl because you
are poking around inside the packet. All the other uses of
xemaclite_readl() are for descriptors etc.
It would be cleaner if you defined a xemaclite_readlbe32. If you use
ioread32be() it will do the endinness swap for you, so you don't need
the ntohl() and the horrible cast.
Andrew