From: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"bhelgaas@google.com" <bhelgaas@google.com>,
"mika.westerberg@linux.intel.com"
<mika.westerberg@linux.intel.com>,
"corbet@lwn.net" <corbet@lwn.net>,
"benh@kernel.crashing.org" <benh@kernel.crashing.org>,
"logang@deltatee.com" <logang@deltatee.com>
Subject: [PATCH v7 2/8] PCI: Skip resource distribution when no hotplug bridges
Date: Mon, 1 Jul 2019 14:23:32 +0000 [thread overview]
Message-ID: <SL2P216MB0187E00E76AA8F503DE5045C80F90@SL2P216MB0187.KORP216.PROD.OUTLOOK.COM> (raw)
If "hotplug_bridges == 0", "!dev->is_hotplug_bridge" is always true, so the
loop that divides the remaining resources among hotplug-capable bridges
does nothing.
Check for "hotplug_bridges == 0" earlier, so we don't even have to compute
the amount of remaining resources. No functional change intended.
Signed-off-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
---
drivers/pci/setup-bus.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index af28af898..04adeebe8 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1887,6 +1887,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
return;
}
+ if (hotplug_bridges == 0)
+ return;
+
/*
* Calculate the total amount of extra resource space we can
* pass to bridges below this one. This is basically the
@@ -1936,8 +1939,6 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
* Distribute available extra resources equally between
* hotplug-capable downstream ports taking alignment into
* account.
- *
- * Here hotplug_bridges is always != 0.
*/
align = pci_resource_alignment(bridge, io_res);
io = div64_ul(available_io, hotplug_bridges);
--
2.20.1
reply other threads:[~2019-07-01 14:23 UTC|newest]
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