net: cdc_ncm: fix 64bit division build error

The upper timer_interval limit is arbitrary and much higher
than anything usable in the real world.  Reducing it from 15s
to ~4s to make the timer_interval fit in an u32 does not make
much difference.  The limit is still outside the practical
bounds.

This eliminates the need for a 64bit timer_interval, fixing a
build error related to 64bit division:

 drivers/built-in.o: In function `cdc_ncm_get_coalesce':
 ak8975.c:(.text+0x1ac994): undefined reference to `__aeabi_uldivmod'

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 2d0caf1..ad2a386 100644 (file)
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -138,7 +138,7 @@ static int cdc_ncm_get_coalesce(struct net_device *netdev,
        ec->tx_max_coalesced_frames = ctx->tx_max / ctx->max_datagram_size;
 
        /* the timer will fire CDC_NCM_TIMER_PENDING_CNT times in a row */
-       ec->tx_coalesce_usecs = (ctx->timer_interval * CDC_NCM_TIMER_PENDING_CNT) / NSEC_PER_USEC;
+       ec->tx_coalesce_usecs = ctx->timer_interval / (NSEC_PER_USEC / CDC_NCM_TIMER_PENDING_CNT);
        return 0;
 }
 
@@ -164,7 +164,7 @@ static int cdc_ncm_set_coalesce(struct net_device *netdev,
                return -EINVAL;
 
        spin_lock_bh(&ctx->mtx);
-       ctx->timer_interval = ec->tx_coalesce_usecs * NSEC_PER_USEC / CDC_NCM_TIMER_PENDING_CNT;
+       ctx->timer_interval = ec->tx_coalesce_usecs * (NSEC_PER_USEC / CDC_NCM_TIMER_PENDING_CNT);
        if (!ctx->timer_interval)
                ctx->tx_timer_pending = 0;
        spin_unlock_bh(&ctx->mtx);

diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index 8c5e388..7c9b484 100644 (file)
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h
@@ -78,7 +78,7 @@
 #define        CDC_NCM_TIMER_PENDING_CNT               2
 #define CDC_NCM_TIMER_INTERVAL_USEC            400UL
 #define CDC_NCM_TIMER_INTERVAL_MIN             5UL
-#define CDC_NCM_TIMER_INTERVAL_MAX             (15UL * USEC_PER_SEC)
+#define CDC_NCM_TIMER_INTERVAL_MAX             (U32_MAX / NSEC_PER_USEC)
 
 #define cdc_ncm_comm_intf_is_mbim(x)  ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \
                                       (x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE)
@@ -104,7 +104,7 @@ struct cdc_ncm_ctx {
        spinlock_t mtx;
        atomic_t stop;
 
-       u64 timer_interval;
+       u32 timer_interval;
        u32 max_ndp_size;
 
        u32 tx_timer_pending;