linux-kernel - RE: [PATCH v2 1/8] PCI: pciehp: Rename pcie

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Message-ID: <92EBB4272BF81E4089A7126EC1E7B284665ABBDA@IRSMSX101.ger.corp.intel.com>
Date:   Tue, 13 Sep 2016 10:05:31 +0000
From:   "Patel, Mayurkumar" <mayurkumar.patel@...el.com>
To:     Bjorn Helgaas <bhelgaas@...gle.com>
CC:     Rajat Jain <rajatja@...gle.com>,
        "MikaWesterberg@...ux.intel.com" <MikaWesterberg@...ux.intel.com>,
        "linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
        "Wysocki, Rafael J" <rafael.j.wysocki@...el.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Busch, Keith" <keith.busch@...el.com>,
        "Tarazona-Duarte, Luis Antonio" 
        <luis.antonio.tarazona-duarte@...el.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        "mika.westerberg@...ux.intel.com" <mika.westerberg@...ux.intel.com>
Subject: RE: [PATCH v2 1/8] PCI: pciehp: Rename pcie_isr() locals for clarity

 
> Rename "detected" and "intr_loc" to "status" and "events" for clarity.
> "status" is the value we read from the Slot Status register; "events" is
> the set of hot-plug events we need to process.  No functional change
> intended.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
> ---
>  drivers/pci/hotplug/pciehp_hpc.c |   46 +++++++++++++++++++++-----------------
>  1 file changed, 25 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index 08e84d6..264df36 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -542,7 +542,7 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
>  	struct pci_bus *subordinate = pdev->subordinate;
>  	struct pci_dev *dev;
>  	struct slot *slot = ctrl->slot;
> -	u16 detected, intr_loc;
> +	u16 status, events;
>  	u8 present;
>  	bool link;
> 
> @@ -555,31 +555,35 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
>  	 * serviced, we need to re-inspect Slot Status register after
>  	 * clearing what is presumed to be the last pending interrupt.
>  	 */
> -	intr_loc = 0;
> +	events = 0;
>  	do {
> -		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &detected);
> -		if (detected == (u16) ~0) {
> +		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
> +		if (status == (u16) ~0) {
>  			ctrl_info(ctrl, "%s: no response from device\n",
>  				  __func__);
>  			return IRQ_HANDLED;
>  		}
> 
> -		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
> -			     PCI_EXP_SLTSTA_PDC |
> -			     PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
> -		detected &= ~intr_loc;
> -		intr_loc |= detected;
> -		if (!intr_loc)
> +		/*
> +		 * Slot Status contains plain status bits as well as event
> +		 * notification bits; right now we only want the event bits.
> +		 */
> +		status &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
> +			   PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC |
> +			   PCI_EXP_SLTSTA_DLLSC);
> +		status &= ~events;
> +		events |= status;
> +		if (!events)
>  			return IRQ_NONE;
> -		if (detected)
> +		if (status)
>  			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
> -						   intr_loc);
> -	} while (detected);
> +						   events);
> +	} while (status);
> 
> -	ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", intr_loc);
> +	ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events);
> 
>  	/* Check Command Complete Interrupt Pending */
> -	if (intr_loc & PCI_EXP_SLTSTA_CC) {
> +	if (events & PCI_EXP_SLTSTA_CC) {
>  		ctrl->cmd_busy = 0;
>  		smp_mb();
>  		wake_up(&ctrl->queue);
> @@ -589,24 +593,24 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
>  		list_for_each_entry(dev, &subordinate->devices, bus_list) {
>  			if (dev->ignore_hotplug) {
>  				ctrl_dbg(ctrl, "ignoring hotplug event %#06x (%s requested no hotplug)\n",
> -					 intr_loc, pci_name(dev));
> +					 events, pci_name(dev));
>  				return IRQ_HANDLED;

Does it make sense here also to return IRQ_NONE? 

>  			}
>  		}
>  	}
> 
> -	if (!(intr_loc & ~PCI_EXP_SLTSTA_CC))
> +	if (!(events & ~PCI_EXP_SLTSTA_CC))
>  		return IRQ_HANDLED;
> 
>  	/* Check Attention Button Pressed */
> -	if (intr_loc & PCI_EXP_SLTSTA_ABP) {
> +	if (events & PCI_EXP_SLTSTA_ABP) {
>  		ctrl_info(ctrl, "Button pressed on Slot(%s)\n",
>  			  slot_name(slot));
>  		pciehp_queue_interrupt_event(slot, INT_BUTTON_PRESS);
>  	}
> 
>  	/* Check Presence Detect Changed */
> -	if (intr_loc & PCI_EXP_SLTSTA_PDC) {
> +	if (events & PCI_EXP_SLTSTA_PDC) {
>  		pciehp_get_adapter_status(slot, &present);
>  		ctrl_info(ctrl, "Card %spresent on Slot(%s)\n",
>  			  present ? "" : "not ", slot_name(slot));
> @@ -615,13 +619,13 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
>  	}
> 
>  	/* Check Power Fault Detected */
> -	if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
> +	if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
>  		ctrl->power_fault_detected = 1;
>  		ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(slot));
>  		pciehp_queue_interrupt_event(slot, INT_POWER_FAULT);
>  	}
> 
> -	if (intr_loc & PCI_EXP_SLTSTA_DLLSC) {
> +	if (events & PCI_EXP_SLTSTA_DLLSC) {
>  		link = pciehp_check_link_active(ctrl);
>  		ctrl_info(ctrl, "slot(%s): Link %s event\n",
>  			  slot_name(slot), link ? "Up" : "Down");

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