[PATCH 3.16 018/157] mac8390: Fix mmio access size probe

From: Ben Hutchings
Date: Sat Aug 10 2019 - 16:54:19 EST


3.16.72-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>

commit bb9e5c5bcd76f4474eac3baf643d7a39f7bac7bb upstream.

The bug that Stan reported is as follows. After a restart, a 16-bit NIC
may be incorrectly identified as a 32-bit NIC and stop working.

mac8390 slot.E: Memory length resource not found, probing
mac8390 slot.E: Farallon EtherMac II-C (type farallon)
mac8390 slot.E: MAC 00:00:c5:30:c2:99, IRQ 61, 32 KB shared memory at 0xfeed0000, 32-bit access.

The bug never arises after a cold start and only intermittently after a
warm start. (I didn't investigate why the bug is intermittent.)

It turns out that memcpy_toio() is deprecated and memcmp_withio() also
has issues. Replacing these calls with mmio accessors fixes the problem.

Reported-and-tested-by: Stan Johnson <userm57@xxxxxxxxx>
Fixes: 2964db0f5904 ("m68k: Mac DP8390 update")
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/net/ethernet/8390/mac8390.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)

--- a/drivers/net/ethernet/8390/mac8390.c
+++ b/drivers/net/ethernet/8390/mac8390.c
@@ -153,8 +153,6 @@ static void dayna_block_input(struct net
static void dayna_block_output(struct net_device *dev, int count,
const unsigned char *buf, int start_page);

-#define memcmp_withio(a, b, c) memcmp((a), (void *)(b), (c))
-
/* Slow Sane (16-bit chunk memory read/write) Cabletron uses this */
static void slow_sane_get_8390_hdr(struct net_device *dev,
struct e8390_pkt_hdr *hdr, int ring_page);
@@ -241,19 +239,26 @@ static enum mac8390_type __init mac8390_

static enum mac8390_access __init mac8390_testio(volatile unsigned long membase)
{
- unsigned long outdata = 0xA5A0B5B0;
- unsigned long indata = 0x00000000;
+ u32 outdata = 0xA5A0B5B0;
+ u32 indata = 0;
+
/* Try writing 32 bits */
- memcpy_toio((void __iomem *)membase, &outdata, 4);
- /* Now compare them */
- if (memcmp_withio(&outdata, membase, 4) == 0)
+ nubus_writel(outdata, membase);
+ /* Now read it back */
+ indata = nubus_readl(membase);
+ if (outdata == indata)
return ACCESS_32;
+
+ outdata = 0xC5C0D5D0;
+ indata = 0;
+
/* Write 16 bit output */
word_memcpy_tocard(membase, &outdata, 4);
/* Now read it back */
word_memcpy_fromcard(&indata, membase, 4);
if (outdata == indata)
return ACCESS_16;
+
return ACCESS_UNKNOWN;
}