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@@ -0,0 +1,62 @@
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+From patchwork Tue Jan 9 14:42:21 2018
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+Content-Type: text/plain; charset="utf-8"
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+MIME-Version: 1.0
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+Content-Transfer-Encoding: 7bit
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+Subject: PCI: dwc: fix enumeration end when reaching root subordinate
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+From: Koen Vandeputte <[email protected]>
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+X-Patchwork-Id: 10152443
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+Message-Id: <[email protected]>
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+To: [email protected]
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+Cc: [email protected], [email protected],
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+ [email protected], [email protected], [email protected],
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+ Koen Vandeputte <[email protected]>,
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+ Mika Westerberg <[email protected]>
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+Date: Tue, 9 Jan 2018 15:42:21 +0100
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+
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+The subordinate value indicates the highest bus number which can be
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+reached downstream though a certain device.
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+
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+Commit a20c7f36bd3d ("PCI: Do not allocate more buses than available in
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+parent")
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+ensures that downstream devices cannot assign busnumbers higher than the
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+upstream device subordinate number, which was indeed illogical.
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+
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+By default, dw_pcie_setup_rc() inits the Root Complex subordinate to a
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+value of 0x01.
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+
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+Due to this combined with above commit, enumeration stops digging deeper
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+downstream as soon as bus num 0x01 has been assigned, which is always
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+the case for a bridge device.
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+
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+This results in all devices behind a bridge bus to remain undetected, as
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+these would be connected to bus 0x02 or higher.
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+
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+Fix this by initializing the RC to a subordinate value of 0xff, meaning
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+that all busses [0x00-0xff] are reachable through this RC.
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+
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+Fixes: a20c7f36bd3d ("PCI: Do not allocate more buses than available in
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+parent")
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+Signed-off-by: Koen Vandeputte <[email protected]>
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+Tested-by: Niklas Cassel <[email protected]>
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+Cc: Mika Westerberg <[email protected]>
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+---
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+
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+Will send separate patches to stable as this file got moved/renamed
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+
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+
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+ drivers/pci/dwc/pcie-designware-host.c | 2 +-
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+ 1 file changed, 1 insertion(+), 1 deletion(-)
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+
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+diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c
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+index bf558df5b7b3..2b5470173196 100644
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+--- a/drivers/pci/dwc/pcie-designware-host.c
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++++ b/drivers/pci/dwc/pcie-designware-host.c
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+@@ -616,7 +616,7 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
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+ /* setup bus numbers */
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+ val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS);
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+ val &= 0xff000000;
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+- val |= 0x00010100;
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++ val |= 0x00ff0100;
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+ dw_pcie_writel_dbi(pci, PCI_PRIMARY_BUS, val);
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+
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+ /* setup command register */
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Tim Harvey