Re: [PATCH v2 1/4] PCI: pciehp: Add pciehp_set_indicators() to jointly set LED indicators

[sathyanarayanan kuppuswamy]

Hi,

On 8/12/19 11:25 AM, sathyanarayanan kuppuswamy wrote:
> Hi,
>
> On 8/11/19 12:59 PM, Denis Efremov wrote:
> > Add pciehp_set_indicators() to set power and attention indicators with a
> > single register write. Thus, avoiding waiting twice for Command 
> > Complete.
> > enum pciehp_indicator introduced to switch between the indicators 
> > statuses.
> >
> > Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
> > ---
> > Â drivers/pci/hotplug/pciehp.hÂÂÂÂ | 14 ++++++++++++
> > Â drivers/pci/hotplug/pciehp_hpc.c | 38 ++++++++++++++++++++++++++++++++
> > Â include/uapi/linux/pci_regs.hÂÂÂ |Â 2 ++
> > Â 3 files changed, 54 insertions(+)
> >
> > diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
> > index 8c51a04b8083..17305a6f01f1 100644
> > --- a/drivers/pci/hotplug/pciehp.h
> > +++ b/drivers/pci/hotplug/pciehp.h
> > @@ -150,6 +150,17 @@ struct controller {
> > Â #define NO_CMD_CMPL(ctrl)ÂÂÂ ((ctrl)->slot_cap & PCI_EXP_SLTCAP_NCCS)
> > Â #define PSN(ctrl)ÂÂÂÂÂÂÂ (((ctrl)->slot_cap & PCI_EXP_SLTCAP_PSN) 
> > >> 19)
> > Â +enum pciehp_indicator {
> > +ÂÂÂ ATTN_NONEÂ = -1,
> > +ÂÂÂ ATTN_ONÂÂÂ =Â 1,
> > +ÂÂÂ ATTN_BLINK =Â 2,
> > +ÂÂÂ ATTN_OFFÂÂ =Â 3,
> > +ÂÂÂ PWR_NONEÂÂ = -1,
> > +ÂÂÂ PWR_ONÂÂÂÂ =Â 1,
> > +ÂÂÂ PWR_BLINKÂ =Â 2,
> > +ÂÂÂ PWR_OFFÂÂÂ =Â 3,
> > +};
> > +
> > Â void pciehp_request(struct controller *ctrl, int action);
> > Â void pciehp_handle_button_press(struct controller *ctrl);
> > Â void pciehp_handle_disable_request(struct controller *ctrl);
> > @@ -167,6 +178,9 @@ int pciehp_power_on_slot(struct controller *ctrl);
> > Â void pciehp_power_off_slot(struct controller *ctrl);
> > Â void pciehp_get_power_status(struct controller *ctrl, u8 *status);
> > Â +void pciehp_set_indicators(struct controller *ctrl,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ enum pciehp_indicator pwr,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ enum pciehp_indicator attn);
> > Â void pciehp_set_attention_status(struct controller *ctrl, u8 status);
> > Â void pciehp_get_latch_status(struct controller *ctrl, u8 *status);
> > Â int pciehp_query_power_fault(struct controller *ctrl);
> > diff --git a/drivers/pci/hotplug/pciehp_hpc.c 
> > b/drivers/pci/hotplug/pciehp_hpc.c
> > index bd990e3371e3..5a690b1579ec 100644
> > --- a/drivers/pci/hotplug/pciehp_hpc.c
> > +++ b/drivers/pci/hotplug/pciehp_hpc.c
> > @@ -443,6 +443,44 @@ void pciehp_set_attention_status(struct 
> > controller *ctrl, u8 value)
> > ÂÂÂÂÂÂÂÂÂÂ pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
> > Â }
> > Â +void pciehp_set_indicators(struct controller *ctrl,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ enum pciehp_indicator pwr,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ enum pciehp_indicator attn)
> > +{
> > +ÂÂÂ u16 cmd = 0, mask = 0;
> > +
> > + if ((!PWR_LED(ctrl) || pwr == PWR_NONE) &&
> > +ÂÂÂÂÂÂÂ (!ATTN_LED(ctrl) || attn == ATTN_NONE))
> > +ÂÂÂÂÂÂÂ return;

Also I think this condition needs to expand to handle the case whether 
pwr != PWR_NONE and !PWR_LED(ctrl) is true.

you need to return for case, pwr = PWR_ON, !PWR_LED(ctrl)=true , 
!ATTN_LED(ctrl)=false, attn=on

> > +
> > +ÂÂÂ switch (pwr) {
> > +ÂÂÂ case PWR_ON:
> > +ÂÂÂ case PWR_BLINK:
> > +ÂÂÂ case PWR_OFF:
> > +ÂÂÂÂÂÂÂ cmd = pwr << PCI_EXP_SLTCTL_PWR_IND_OFFSET;
> > +ÂÂÂÂÂÂÂ mask = PCI_EXP_SLTCTL_PIC;
> > +ÂÂÂÂÂÂÂ break;
> > +ÂÂÂ default:
> > +ÂÂÂÂÂÂÂ break;
> > +ÂÂÂ }
> Do we need to switch case here ? if (pwr > 0) {} should work right ?
> > +
> > +ÂÂÂ switch (attn) {
> > +ÂÂÂ case ATTN_ON:
> > +ÂÂÂ case ATTN_BLINK:
> > +ÂÂÂ case ATTN_OFF:
> > +ÂÂÂÂÂÂÂ cmd |= attn << PCI_EXP_SLTCTL_ATTN_IND_OFFSET;
> > +ÂÂÂÂÂÂÂ mask |= PCI_EXP_SLTCTL_AIC;
> > +ÂÂÂÂÂÂÂ break;
> > +ÂÂÂ default:
> > +ÂÂÂÂÂÂÂ break;
> > +ÂÂÂ }
> Same here. if (attn > 0) {}
> > +
> > +ÂÂÂ pcie_write_cmd_nowait(ctrl, cmd, mask);
> > +ÂÂÂ ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
> > +ÂÂÂÂÂÂÂÂ pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
> > +ÂÂÂÂÂÂÂÂ cmd);
> > +}
> > +
> > Â void pciehp_green_led_on(struct controller *ctrl)
> > Â {
> > ÂÂÂÂÂ if (!PWR_LED(ctrl))
> > diff --git a/include/uapi/linux/pci_regs.h 
> > b/include/uapi/linux/pci_regs.h
> > index f28e562d7ca8..18722d1f54a0 100644
> > --- a/include/uapi/linux/pci_regs.h
> > +++ b/include/uapi/linux/pci_regs.h
> > @@ -591,10 +591,12 @@
> >  #define PCI_EXP_SLTCTL_CCIE 0x0010 /* Command Completed 
> > Interrupt Enable */
> >  #define PCI_EXP_SLTCTL_HPIE 0x0020 /* Hot-Plug Interrupt 
> > Enable */
> >  #define PCI_EXP_SLTCTL_AIC 0x00c0 /* Attention Indicator 
> > Control */
> > +#define PCI_EXP_SLTCTL_ATTN_IND_OFFSET 0x6 /* Attention Indicator 
> > Offset */
> >  #define PCI_EXP_SLTCTL_ATTN_IND_ON 0x0040 /* Attention 
> > Indicator on */
> >  #define PCI_EXP_SLTCTL_ATTN_IND_BLINK 0x0080 /* Attention 
> > Indicator blinking */
> >  #define PCI_EXP_SLTCTL_ATTN_IND_OFF 0x00c0 /* Attention 
> > Indicator off */
> >  #define PCI_EXP_SLTCTL_PIC 0x0300 /* Power Indicator Control */
> > +#define PCI_EXP_SLTCTL_PWR_IND_OFFSET 0x8 /* Power Indicator 
> > Offset */
> >  #define PCI_EXP_SLTCTL_PWR_IND_ON 0x0100 /* Power Indicator on */
> >  #define PCI_EXP_SLTCTL_PWR_IND_BLINK 0x0200 /* Power Indicator 
> > blinking */
> >  #define PCI_EXP_SLTCTL_PWR_IND_OFF 0x0300 /* Power Indicator 
> > off */
--
Sathyanarayanan Kuppuswamy
Linux kernel developer