net: 6pack: Fix tx timeout and slot time

stable inclusion
from stable-5.10.70
commit 890e25c424eac432ed2d4c96376b51275bd031b1
bugzilla: 182949 https://gitee.com/openeuler/kernel/issues/I4I3GQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=890e25c424eac432ed2d4c96376b51275bd031b1

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

[ Upstream commit 3c0d2a46 ]

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: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

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 */