Hi all!
I'm find then ftdi_sio.c in 2.4.37.8 kernel have next bug: if I have
three ftdi-232 simultaneously connected to middle-loaded host,
application which use one of them will hung in driver, usually during
few hour.
At now i try to revise that driver and also I review driver in 2.6.32
and do few minor fixes + found out possible buggy place.
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1) function ftdi_232am_baud_base_to_divisor() in 2.6.32 have next view:
static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base)
{
unsigned short int divisor;
/* divisor shifted 3 bits to the left */
int divisor3 = base / 2 / baud;
if ((divisor3 & 0x7) == 7)
divisor3++; /* round x.7/8 up to x+1 */
divisor = divisor3 >> 3;
divisor3 &= 0x7;
if (divisor3 == 1)
divisor |= 0xc000; /* 0.125 */
else if (divisor3 >= 4)
divisor |= 0x4000; /* 0.5 */
else if (divisor3 != 0)
divisor |= 0x8000; /* 0.25 */
/// @warning possible at this place we have bug
else if (divisor == 1)
divisor = 0; /* special case for maximum baud rate */
return divisor;
}
but POSSIBLE may be need:
static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base)
{
unsigned short int divisor;
/* divisor shifted 3 bits to the left */
int divisor3 = base / 2 / baud;
if ((divisor3 & 0x7) == 7)
divisor3++; /* round x.7/8 up to x+1 */
divisor = divisor3 >> 3;
divisor3 &= 0x7;
if (divisor3 == 1)
divisor |= 0xc000; /* 0.125 */
else if (divisor3 >= 4)
divisor |= 0x4000; /* 0.5 */
else if (divisor3 != 0)
divisor |= 0x8000; /* 0.25 */
if (divisor == 1)
divisor = 0; /* special case for maximum baud rate */
return divisor;
}
Can anyone guide me?
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2) In the attached patch I do few small fixes. About half of them must
be merged into kernel trunk
\\wbr Vitaly Chernookiy
Attachment:
ftdi_sio.c.diff
Description: Binary data
