| From c9bd28233b6d0d82ac3ba0215723be0a8262c39c Mon Sep 17 00:00:00 2001 |
| From: Arnd Bergmann <arnd@arndb.de> |
| Date: Thu, 24 Nov 2016 17:26:22 +0100 |
| Subject: irda: fix overly long udelay() |
| |
| From: Arnd Bergmann <arnd@arndb.de> |
| |
| commit c9bd28233b6d0d82ac3ba0215723be0a8262c39c upstream. |
| |
| irda_get_mtt() returns a hardcoded '10000' in some cases, |
| and with gcc-7, we get a build error because this triggers a |
| compile-time check in udelay(): |
| |
| drivers/net/irda/w83977af_ir.o: In function `w83977af_hard_xmit': |
| w83977af_ir.c:(.text.w83977af_hard_xmit+0x14c): undefined reference to `__bad_udelay' |
| |
| Older compilers did not run into this because they either did not |
| completely inline the irda_get_mtt() or did not consider the |
| 10000 value a constant expression. |
| |
| The code has been wrong since the start of git history. |
| |
| Signed-off-by: Arnd Bergmann <arnd@arndb.de> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Cc: Guenter Roeck <linux@roeck-us.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/net/irda/w83977af_ir.c | 4 +++- |
| 1 file changed, 3 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/net/irda/w83977af_ir.c |
| +++ b/drivers/net/irda/w83977af_ir.c |
| @@ -518,7 +518,9 @@ static netdev_tx_t w83977af_hard_xmit(st |
| |
| mtt = irda_get_mtt(skb); |
| pr_debug("%s(%ld), mtt=%d\n", __func__ , jiffies, mtt); |
| - if (mtt) |
| + if (mtt > 1000) |
| + mdelay(mtt/1000); |
| + else if (mtt) |
| udelay(mtt); |
| |
| /* Enable DMA interrupt */ |
