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| author |   Arnd Bergmann <arnd@arndb.de> | 2018-07-06 15:36:07 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-07-07 21:16:53 +0900 |
| commit | 8f704ef666406fc5e42032308a2b366ea7bca846 (patch) | |
| tree | ad71c6df489e7b87930614eddcc7d096000560a8 | |
| parent | tipc: extend link reset criteria for stale packet retransmission (diff) | |
| download | linux-dev-8f704ef666406fc5e42032308a2b366ea7bca846.tar.xz linux-dev-8f704ef666406fc5e42032308a2b366ea7bca846.zip | |
stmmac: fix signed 64-bit division
I link error on 32-bit ARM points to yet another arithmetic bug:
drivers/net/ethernet/stmicro/stmmac/stmmac_tc.o: In function `tc_setup_cbs':
stmmac_tc.c:(.text+0x148): undefined reference to `__aeabi_uldivmod'
stmmac_tc.c:(.text+0x1fc): undefined reference to `__aeabi_uldivmod'
stmmac_tc.c:(.text+0x308): undefined reference to `__aeabi_uldivmod'
stmmac_tc.c:(.text+0x320): undefined reference to `__aeabi_uldivmod'
stmmac_tc.c:(.text+0x33c): undefined reference to `__aeabi_uldivmod'
drivers/net/ethernet/stmicro/stmmac/stmmac_tc.o:stmmac_tc.c:(.text+0x3a4): more undefined references to `__aeabi_uldivmod' follow
I observe that the last change to add the 'ul' prefix was incorrect,
as it did not turn the result of the multiplication into a 64-bit
expression on 32-bit architectures. Further, it seems that the
do_div() macro gets confused by the fact that we pass a signed
variable rather than unsigned into it.
This changes the code to instead use the div_s64() helper that is
meant for signed division, along with changing the constant suffix
to 'll' to actually make it a 64-bit argument everywhere, fixing
both of the issues I pointed out.
I'm not completely convinced that this makes the code correct, but
I'm fairly sure that we have two problems less than before.
Fixes: 1f705bc61aee ("net: stmmac: Add support for CBS QDISC")
Fixes: c18a9c096683 ("net: stmmac_tc: use 64-bit arithmetic instead of 32-bit")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c index 8fedc288d138..1a96dd9c1091 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c @@ -321,18 +321,16 @@ static int tc_setup_cbs(struct stmmac_priv *priv, speed_div = (priv->speed == SPEED_100) ? 100000 : 1000000; /* Final adjustments for HW */ - value = qopt->idleslope * 1024UL * ptr; - do_div(value, speed_div); + value = div_s64(qopt->idleslope * 1024ll * ptr, speed_div); priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0); - value = -qopt->sendslope * 1024UL * ptr; - do_div(value, speed_div); + value = div_s64(-qopt->sendslope * 1024ll * ptr, speed_div); priv->plat->tx_queues_cfg[queue].send_slope = value & GENMASK(31, 0); - value = qopt->hicredit * 1024UL * 8; + value = qopt->hicredit * 1024ll * 8; priv->plat->tx_queues_cfg[queue].high_credit = value & GENMASK(31, 0); - value = qopt->locredit * 1024UL * 8; + value = qopt->locredit * 1024ll * 8; priv->plat->tx_queues_cfg[queue].low_credit = value & GENMASK(31, 0); ret = stmmac_config_cbs(priv, priv->hw, |