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media: flexcop-i2c: get rid of KERN_CONT 

Coverity complains about werid stuff at the debug logic:

	CID 113542 (#1 of 1): Out-of-bounds access (ARRAY_VS_SINGLETON)10.
	callee_ptr_arith: Passing buf to function flexcop_i2c_write4
	which uses it as an array. This might corrupt or misinterpret
	adjacent memory locations.

Instead of directly addressing the issue there, let's rework at
the logic there.

On newer kernels, KERN_CONT does nothing, as the previous message
won't wait for a continuation. Also, both flexcop_i2c_read4() and
flexcop_i2c_write4(), called by it, will print stuff if (debug &4).

So, the way it is is too buggy.

There are two kinds of debug stuff there: deb_i2c() and a code hidden
under #ifdef DUMP_I2C_MESSAGES, with can't be selected without touching
the source code.

Also, if both debug & 0x4 and DUMP_I2C_MESSAGES, flexcop_i2c_request()
will emit two debug messages per call with different data,
with sounds messy.

Simplify it by getting rid of DUMP_I2C_MESSAGES and adding a new
flag to debug (0x40), and making the debug logic there more
consistent.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Mauro Carvalho Chehab 2018-04-23 08:29:09 -04:00 committed by Mauro Carvalho Chehab
parent 366b401001
commit 25d4affb0c
3 changed files with 21 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
drivers/media/common/b2c2/flexcop-i2c.c
View File

@ -105,40 +105,36 @@ static int flexcop_i2c_write4(struct flexcop_device *fc,
}
int flexcop_i2c_request(struct flexcop_i2c_adapter *i2c,
flexcop_access_op_t op, u8 chipaddr, u8 addr, u8 *buf, u16 len)
flexcop_access_op_t op, u8 chipaddr,
u8 start_addr, u8 *buf, u16 size)
{
int ret;
#ifdef DUMP_I2C_MESSAGES
int i;
#endif
int len = size;
u8 *p;
u8 addr = start_addr;
u16 bytes_to_transfer;
flexcop_ibi_value r100;
deb_i2c("op = %d\n",op);
deb_i2c("port %d %s(%02x): register %02x, size: %d\n",
i2c->port,
op == FC_READ ? "rd" : "wr",
chipaddr, start_addr, size);
r100.raw = 0;
r100.tw_sm_c_100.chipaddr = chipaddr;
r100.tw_sm_c_100.twoWS_rw = op;
r100.tw_sm_c_100.twoWS_port_reg = i2c->port;
#ifdef DUMP_I2C_MESSAGES
printk(KERN_DEBUG "%d ", i2c->port);
if (op == FC_READ)
printk(KERN_CONT "rd(");
else
printk(KERN_CONT "wr(");
printk(KERN_CONT "%02x): %02x ", chipaddr, addr);
#endif
/* in that case addr is the only value ->
* we write it twice as baseaddr and val0
* BBTI is doing it like that for ISL6421 at least */
if (i2c->no_base_addr && len == 0 && op == FC_WRITE) {
buf = &addr;
buf = &start_addr;
len = 1;
}
p = buf;
while (len != 0) {
bytes_to_transfer = len > 4 ? 4 : len;
@ -146,26 +142,21 @@ int flexcop_i2c_request(struct flexcop_i2c_adapter *i2c,
r100.tw_sm_c_100.baseaddr = addr;
if (op == FC_READ)
ret = flexcop_i2c_read4(i2c, r100, buf);
ret = flexcop_i2c_read4(i2c, r100, p);
else
ret = flexcop_i2c_write4(i2c->fc, r100, buf);
#ifdef DUMP_I2C_MESSAGES
for (i = 0; i < bytes_to_transfer; i++)
printk(KERN_CONT "%02x ", buf[i]);
#endif
ret = flexcop_i2c_write4(i2c->fc, r100, p);
if (ret < 0)
return ret;
buf += bytes_to_transfer;
p += bytes_to_transfer;
addr += bytes_to_transfer;
len -= bytes_to_transfer;
}
#ifdef DUMP_I2C_MESSAGES
printk(KERN_CONT "\n");
#endif
deb_i2c_dump("port %d %s(%02x): register %02x: %*ph\n",
i2c->port,
op == FC_READ ? "rd" : "wr",
chipaddr, start_addr, size, buf);
return 0;
}

2
drivers/media/common/b2c2/flexcop.c
View File

@ -42,7 +42,7 @@ int b2c2_flexcop_debug;
EXPORT_SYMBOL_GPL(b2c2_flexcop_debug);
module_param_named(debug, b2c2_flexcop_debug, int, 0644);
MODULE_PARM_DESC(debug,
"set debug level (1=info,2=tuner,4=i2c,8=ts,16=sram,32=reg (|-able))."
"set debug level (1=info,2=tuner,4=i2c,8=ts,16=sram,32=reg,64=i2cdump (|-able))."
DEBSTATUS);
#undef DEBSTATUS

1
drivers/media/common/b2c2/flexcop.h
View File

@ -26,5 +26,6 @@ extern int b2c2_flexcop_debug;
#define deb_ts(args...) dprintk(0x08, args)
#define deb_sram(args...) dprintk(0x10, args)
#define deb_rdump(args...) dprintk(0x20, args)
#define deb_i2c_dump(args...) dprintk(0x40, args)
#endif