6.4-stable review patch. If anyone has any objections, please let me know.
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From: Sven Peter sven@svenpeter.dev
[ Upstream commit d8650c0c2aa2e413594e4cb0faafa9958c1d7782 ]
The apple_pcie_setup_port() function computes ilog2(pcie->nvecs) to set up the number of MSIs available for each port. However, it's called before apple_msi_init(), which initializes pcie->nvecs.
Luckily, pcie->nvecs is part of kzalloc()-ed structure and, as such, initialized as zero. ilog2(0) happens to be 0xffffffff which then simply configures more MSIs in hardware than we have. This doesn't break anything because we never hand out those vectors.
Thus, swap the order of the two calls so that the correctly initialized value is then used.
[kwilczynski: commit log] Link: https://lore.kernel.org/linux-pci/20230311133453.63246-1-sven@svenpeter.dev Fixes: 476c41ed4597 ("PCI: apple: Implement MSI support") Signed-off-by: Sven Peter sven@svenpeter.dev Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org Reviewed-by: Marc Zyngier maz@kernel.org Reviewed-by: Alyssa Rosenzweig alyssa@rosenzweig.io Reviewed-by: Eric Curtin ecurtin@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/pcie-apple.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c index 66f37e403a09c..2340dab6cd5bd 100644 --- a/drivers/pci/controller/pcie-apple.c +++ b/drivers/pci/controller/pcie-apple.c @@ -783,6 +783,10 @@ static int apple_pcie_init(struct pci_config_window *cfg) cfg->priv = pcie; INIT_LIST_HEAD(&pcie->ports);
+ ret = apple_msi_init(pcie); + if (ret) + return ret; + for_each_child_of_node(dev->of_node, of_port) { ret = apple_pcie_setup_port(pcie, of_port); if (ret) { @@ -792,7 +796,7 @@ static int apple_pcie_init(struct pci_config_window *cfg) } }
- return apple_msi_init(pcie); + return 0; }
static int apple_pcie_probe(struct platform_device *pdev)