From: Bjorn Helgaas <helgaas@kernel.org>
To: Keith Busch <keith.busch@intel.com>
Cc: linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCHv4] pciehp: Let user control LED status
Date: Fri, 23 Sep 2016 09:32:22 -0500 [thread overview]
Message-ID: <20160923143222.GE1514@localhost> (raw)
In-Reply-To: <1473784319-6137-1-git-send-email-keith.busch@intel.com>
On Tue, Sep 13, 2016 at 10:31:59AM -0600, Keith Busch wrote:
> This patch adds a new flag to the pci_dev structure instructing pciehp
> to not interpret PCIe slot LED indicators. The pciehp driver will instead
> allow all LED control from the user by setting the slot control indicators
> as the user requested through sysfs. This is preparing for domain devices
> that repurpose these control bits for non-standard use.
>
> Signed-off-by: Keith Busch <keith.busch@intel.com>
BTW, I think this turned out really well. It's small and clean and I
think it's safe in terms of races and so on. Thanks a lot for pushing
on this!
> ---
> v3 -> v4:
>
> Fixing symbol usage by generating patch from the tree that compiles
> correctly.
>
> drivers/pci/hotplug/pciehp.h | 5 +++++
> drivers/pci/hotplug/pciehp_core.c | 3 +++
> drivers/pci/hotplug/pciehp_hpc.c | 27 +++++++++++++++++++++++++++
> include/linux/pci.h | 1 +
> 4 files changed, 36 insertions(+)
>
> diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
> index e764918..725078d 100644
> --- a/drivers/pci/hotplug/pciehp.h
> +++ b/drivers/pci/hotplug/pciehp.h
> @@ -152,6 +152,11 @@ bool pciehp_check_link_active(struct controller *ctrl);
> void pciehp_release_ctrl(struct controller *ctrl);
> int pciehp_reset_slot(struct slot *slot, int probe);
>
> +int pciehp_set_raw_attention_status(struct hotplug_slot *hotplug_slot,
> + u8 status);
> +int pciehp_get_raw_attention_status(struct hotplug_slot *hotplug_slot,
> + u8 *status);
> +
> static inline const char *slot_name(struct slot *slot)
> {
> return hotplug_slot_name(slot->hotplug_slot);
> diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
> index fb0f863..68b7aeb 100644
> --- a/drivers/pci/hotplug/pciehp_core.c
> +++ b/drivers/pci/hotplug/pciehp_core.c
> @@ -113,6 +113,9 @@ static int init_slot(struct controller *ctrl)
> if (ATTN_LED(ctrl)) {
> ops->get_attention_status = get_attention_status;
> ops->set_attention_status = set_attention_status;
> + } else if (ctrl->pcie->port->user_leds) {
> + ops->get_attention_status = pciehp_get_raw_attention_status;
> + ops->set_attention_status = pciehp_set_raw_attention_status;
> }
>
> /* register this slot with the hotplug pci core */
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index 08e84d6..5ab8604 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -355,6 +355,18 @@ static int pciehp_link_enable(struct controller *ctrl)
> return __pciehp_link_set(ctrl, true);
> }
>
> +int pciehp_get_raw_attention_status(struct hotplug_slot *hotplug_slot,
> + u8 *status)
> +{
> + struct slot *slot = hotplug_slot->private;
> + struct pci_dev *pdev = ctrl_dev(slot->ctrl);
> + u16 slot_ctrl;
> +
> + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
> + *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC)) >> 6;
> + return 0;
> +}
> +
> void pciehp_get_attention_status(struct slot *slot, u8 *status)
> {
> struct controller *ctrl = slot->ctrl;
> @@ -431,6 +443,17 @@ int pciehp_query_power_fault(struct slot *slot)
> return !!(slot_status & PCI_EXP_SLTSTA_PFD);
> }
>
> +int pciehp_set_raw_attention_status(struct hotplug_slot *hotplug_slot,
> + u8 status)
> +{
> + struct slot *slot = hotplug_slot->private;
> + struct controller *ctrl = slot->ctrl;
> +
> + pcie_write_cmd_nowait(ctrl, status << 6,
> + PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC);
> + return 0;
> +}
> +
> void pciehp_set_attention_status(struct slot *slot, u8 value)
> {
> struct controller *ctrl = slot->ctrl;
> @@ -804,6 +827,10 @@ struct controller *pcie_init(struct pcie_device *dev)
> }
> ctrl->pcie = dev;
> pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
> +
> + if (pdev->user_leds)
> + slot_cap &= ~(PCI_EXP_SLTCAP_AIP | PCI_EXP_SLTCAP_PIP);
> +
> ctrl->slot_cap = slot_cap;
> mutex_init(&ctrl->ctrl_lock);
> init_waitqueue_head(&ctrl->queue);
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 7256f33..f41bbca 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -308,6 +308,7 @@ struct pci_dev {
> powered on/off by the
> corresponding bridge */
> unsigned int ignore_hotplug:1; /* Ignore hotplug events */
> + unsigned int user_leds:1; /* User excluse LED SlotCtl */
> unsigned int d3_delay; /* D3->D0 transition time in ms */
> unsigned int d3cold_delay; /* D3cold->D0 transition time in ms */
>
> --
> 2.7.2
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
prev parent reply other threads:[~2016-09-23 14:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-13 16:31 [PATCHv4] pciehp: Let user control LED status Keith Busch
2016-09-23 14:30 ` Bjorn Helgaas
2016-09-23 14:32 ` Bjorn Helgaas [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160923143222.GE1514@localhost \
--to=helgaas@kernel.org \
--cc=bhelgaas@google.com \
--cc=keith.busch@intel.com \
--cc=linux-pci@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).