diff options
Diffstat (limited to 'target/linux')
| -rw-r--r-- | target/linux/generic/pending-4.9/812-pci-dwc-fix-enumeration.patch | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/target/linux/generic/pending-4.9/812-pci-dwc-fix-enumeration.patch b/target/linux/generic/pending-4.9/812-pci-dwc-fix-enumeration.patch new file mode 100644 index 0000000000..5092aba53f --- /dev/null +++ b/target/linux/generic/pending-4.9/812-pci-dwc-fix-enumeration.patch @@ -0,0 +1,62 @@ +From patchwork Tue Jan 9 14:42:21 2018 +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: 7bit +Subject: PCI: dwc: fix enumeration end when reaching root subordinate +From: Koen Vandeputte <koen.vandeputte@ncentric.com> +X-Patchwork-Id: 10152443 +Message-Id: <1515508941-20055-1-git-send-email-koen.vandeputte@ncentric.com> +To: linux-pci@vger.kernel.org +Cc: bhelgaas@google.com, lorenzo.pieralisi@arm.com, + Joao.Pinto@synopsys.com, jingoohan1@gmail.com, niklas.cassel@axis.com, + Koen Vandeputte <koen.vandeputte@ncentric.com>, + Mika Westerberg <mika.westerberg@linux.intel.com> +Date: Tue, 9 Jan 2018 15:42:21 +0100 + +The subordinate value indicates the highest bus number which can be +reached downstream though a certain device. + +Commit a20c7f36bd3d ("PCI: Do not allocate more buses than available in +parent") +ensures that downstream devices cannot assign busnumbers higher than the +upstream device subordinate number, which was indeed illogical. + +By default, dw_pcie_setup_rc() inits the Root Complex subordinate to a +value of 0x01. + +Due to this combined with above commit, enumeration stops digging deeper +downstream as soon as bus num 0x01 has been assigned, which is always +the case for a bridge device. + +This results in all devices behind a bridge bus to remain undetected, as +these would be connected to bus 0x02 or higher. + +Fix this by initializing the RC to a subordinate value of 0xff, meaning +that all busses [0x00-0xff] are reachable through this RC. + +Fixes: a20c7f36bd3d ("PCI: Do not allocate more buses than available in +parent") +Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com> +Tested-by: Niklas Cassel <niklas.cassel@axis.com> +Cc: Mika Westerberg <mika.westerberg@linux.intel.com> +--- + +Will send separate patches to stable as this file got moved/renamed + + + drivers/pci/host/pcie-designware.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c +index bf558df5b7b3..2b5470173196 100644 +--- a/drivers/pci/host/pcie-designware.c ++++ b/drivers/pci/host/pcie-designware.c +@@ -861,7 +861,7 @@ void dw_pcie_setup_rc(struct pcie_port * + /* setup bus numbers */ + val = dw_pcie_readl_rc(pp, PCI_PRIMARY_BUS); + val &= 0xff000000; +- val |= 0x00010100; ++ val |= 0x00ff0100; + dw_pcie_writel_rc(pp, PCI_PRIMARY_BUS, val); + + /* setup command register */ |