Re: [RFC PATCH v4 3/7] PCI: Ignore resource_alignment if PCI_PROBE_ONLY was set
From: Alex Williamson
Date: Wed Mar 16 2016 - 12:32:07 EST
On Mon, 7 Mar 2016 15:48:34 +0800
Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx> wrote:
> The resource_alignment will releases memory resources
> allocated by firmware so that kernel can reassign new
> resources later on. But this will cause the problem
> that no resources can be allocated by kernel if
> PCI_PROBE_ONLY was set, e.g. on pSeries platform
> because PCI_PROBE_ONLY force kernel to use firmware
> setup and not to reassign any resources.
> To solve this problem, this patch ignores
> resource_alignment if PCI_PROBE_ONLY was set.
> Signed-off-by: Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx>
> Documentation/kernel-parameters.txt | 2 ++
> drivers/pci/probe.c | 3 ++-
> 2 files changed, 4 insertions(+), 1 deletion(-)
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index d8b29ab..8028631 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -2922,6 +2922,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> windows need to be expanded.
> noresize: Don't change the resources' sizes when
> reassigning alignment.
> + Note that this option will not work if
> + PCI_PROBE_ONLY is set.
How would a user have any idea if this is set?
> ecrc= Enable/disable PCIe ECRC (transaction layer
> end-to-end CRC checking).
> bios: Use BIOS/firmware settings. This is the
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 6d7ab9b..bc31cad 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1719,7 +1719,8 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> pci_fixup_device(pci_fixup_header, dev);
> /* moved out from quirk header fixup code */
> - pci_reassigndev_resource_alignment(dev);
> + if (!pci_has_flag(PCI_PROBE_ONLY))
> + pci_reassigndev_resource_alignment(dev);
> /* Clear the state_saved flag. */
> dev->state_saved = false;