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    Subject[PATCH 4.9 28/57] net: 6pack: Fix tx timeout and slot time
    Date
    From: Guenter Roeck <linux@roeck-us.net>

    [ Upstream commit 3c0d2a46c0141913dc6fd126c57d0615677d946e ]

    tx timeout and slot time are currently specified in units of HZ. On
    Alpha, HZ is defined as 1024. When building alpha:allmodconfig, this
    results in the following error message.

    drivers/net/hamradio/6pack.c: In function 'sixpack_open':
    drivers/net/hamradio/6pack.c:71:41: error:
    unsigned conversion from 'int' to 'unsigned char'
    changes value from '256' to '0'

    In the 6PACK protocol, tx timeout is specified in units of 10 ms and
    transmitted over the wire:

    https://www.linux-ax25.org/wiki/6PACK

    Defining a value dependent on HZ doesn't really make sense, and
    presumably comes from the (very historical) situation where HZ was
    originally 100.

    Note that the SIXP_SLOTTIME use explicitly is about 10ms granularity:

    mod_timer(&sp->tx_t, jiffies + ((when + 1) * HZ) / 100);

    and the SIXP_TXDELAY walue is sent as a byte over the wire.

    Signed-off-by: Guenter Roeck <linux@roeck-us.net>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/net/hamradio/6pack.c | 4 ++--
    1 file changed, 2 insertions(+), 2 deletions(-)

    diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
    index e510dbda77e5..96fb2a2a59f0 100644
    --- a/drivers/net/hamradio/6pack.c
    +++ b/drivers/net/hamradio/6pack.c
    @@ -68,9 +68,9 @@
    #define SIXP_DAMA_OFF 0

    /* default level 2 parameters */
    -#define SIXP_TXDELAY (HZ/4) /* in 1 s */
    +#define SIXP_TXDELAY 25 /* 250 ms */
    #define SIXP_PERSIST 50 /* in 256ths */
    -#define SIXP_SLOTTIME (HZ/10) /* in 1 s */
    +#define SIXP_SLOTTIME 10 /* 100 ms */
    #define SIXP_INIT_RESYNC_TIMEOUT (3*HZ/2) /* in 1 s */
    #define SIXP_RESYNC_TIMEOUT 5*HZ /* in 1 s */

    --
    2.33.0


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