diff options
Diffstat (limited to 'target/linux/mvebu/patches-5.4/024-PCI-aardvark-Don-t-touch-PCIe-registers-if-no-card-c.patch')
-rw-r--r-- | target/linux/mvebu/patches-5.4/024-PCI-aardvark-Don-t-touch-PCIe-registers-if-no-card-c.patch | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/target/linux/mvebu/patches-5.4/024-PCI-aardvark-Don-t-touch-PCIe-registers-if-no-card-c.patch b/target/linux/mvebu/patches-5.4/024-PCI-aardvark-Don-t-touch-PCIe-registers-if-no-card-c.patch new file mode 100644 index 0000000000..dfc068c8cb --- /dev/null +++ b/target/linux/mvebu/patches-5.4/024-PCI-aardvark-Don-t-touch-PCIe-registers-if-no-card-c.patch @@ -0,0 +1,50 @@ +From 70e380250c3621c55ff218cbaf2272830d9dbb1d Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org> +Date: Thu, 2 Jul 2020 10:30:36 +0200 +Subject: [PATCH] PCI: aardvark: Don't touch PCIe registers if no card + connected +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +When there is no PCIe card connected and advk_pcie_rd_conf() or +advk_pcie_wr_conf() is called for PCI bus which doesn't belong to emulated +root bridge, the aardvark driver throws the following error message: + + advk-pcie d0070000.pcie: config read/write timed out + +Obviously accessing PCIe registers of disconnected card is not possible. + +Extend check in advk_pcie_valid_device() function for validating +availability of PCIe bus. If PCIe link is down, then the device is marked +as Not Found and the driver does not try to access these registers. + +This is just an optimization to prevent accessing PCIe registers when card +is disconnected. Trying to access PCIe registers of disconnected card does +not cause any crash, kernel just needs to wait for a timeout. So if card +disappear immediately after checking for PCIe link (before accessing PCIe +registers), it does not cause any problems. + +Link: https://lore.kernel.org/r/20200702083036.12230-1-pali@kernel.org +Signed-off-by: Pali Rohár <pali@kernel.org> +Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> +--- + drivers/pci/controller/pci-aardvark.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +--- a/drivers/pci/controller/pci-aardvark.c ++++ b/drivers/pci/controller/pci-aardvark.c +@@ -639,6 +639,13 @@ static bool advk_pcie_valid_device(struc + if ((bus->number == pcie->root_bus_nr) && PCI_SLOT(devfn) != 0) + return false; + ++ /* ++ * If the link goes down after we check for link-up, nothing bad ++ * happens but the config access times out. ++ */ ++ if (bus->number != pcie->root_bus_nr && !advk_pcie_link_up(pcie)) ++ return false; ++ + return true; + } + |