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* [PATCH] PCI: tegra: Disable PTM capabilities for EP mode
@ 2021-03-05  8:12 Om Prakash Singh
  2021-03-05 12:19 ` Bjorn Helgaas
  0 siblings, 1 reply; 4+ messages in thread
From: Om Prakash Singh @ 2021-03-05  8:12 UTC (permalink / raw)
  To: vidyas, jingoohan1, gustavo.pimentel, lorenzo.pieralisi, amurray,
	bhelgaas, kishon, thierry.reding
  Cc: Jisheng.Zhang, jonathanh, linux-pci, linux-kernel, kthota,
	mmaddireddy, oop.singh, Om Prakash Singh

PCIe EP compliance expect PTM capabilities (ROOT_CAPABLE, RES_CAPABLE,
CLK_GRAN) to be disabled.

Signed-off-by: Om Prakash Singh <omp@nvidia.com>
---
 drivers/pci/controller/dwc/pcie-tegra194.c | 17 ++++++++++++++++-
 include/uapi/linux/pci_regs.h              |  1 +
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 6fa216e..a588312 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1639,7 +1639,7 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	struct dw_pcie *pci = &pcie->pci;
 	struct dw_pcie_ep *ep = &pci->ep;
 	struct device *dev = pcie->dev;
-	u32 val;
+	u32 val, ptm_cap_base = 0;
 	int ret;
 
 	if (pcie->ep_state == EP_STATE_ENABLED)
@@ -1760,6 +1760,21 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 						      PCI_CAP_ID_EXP);
 	clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
 
+	/* Disable PTM root and responder capability */
+	ptm_cap_base = dw_pcie_find_ext_capability(&pcie->pci,
+						   PCI_EXT_CAP_ID_PTM);
+	if (ptm_cap_base) {
+		dw_pcie_dbi_ro_wr_en(pci);
+		val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
+		val &= ~PCI_PTM_CAP_ROOT;
+		dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
+
+		val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
+		val &= ~(PCI_PTM_CAP_RES | PCI_PTM_GRANULARITY_MASK);
+		dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
+		dw_pcie_dbi_ro_wr_dis(pci);
+	}
+
 	val = (ep->msi_mem_phys & MSIX_ADDR_MATCH_LOW_OFF_MASK);
 	val |= MSIX_ADDR_MATCH_LOW_OFF_EN;
 	dw_pcie_writel_dbi(pci, MSIX_ADDR_MATCH_LOW_OFF, val);
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index e709ae8..9dd6f8d 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -1050,6 +1050,7 @@
 /* Precision Time Measurement */
 #define PCI_PTM_CAP			0x04	    /* PTM Capability */
 #define  PCI_PTM_CAP_REQ		0x00000001  /* Requester capable */
+#define  PCI_PTM_CAP_RES		0x00000002  /* Responder capable */
 #define  PCI_PTM_CAP_ROOT		0x00000004  /* Root capable */
 #define  PCI_PTM_GRANULARITY_MASK	0x0000FF00  /* Clock granularity */
 #define PCI_PTM_CTRL			0x08	    /* PTM Control */
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] PCI: tegra: Disable PTM capabilities for EP mode
  2021-03-05  8:12 [PATCH] PCI: tegra: Disable PTM capabilities for EP mode Om Prakash Singh
@ 2021-03-05 12:19 ` Bjorn Helgaas
  2021-03-05 18:13   ` Vidya Sagar
  0 siblings, 1 reply; 4+ messages in thread
From: Bjorn Helgaas @ 2021-03-05 12:19 UTC (permalink / raw)
  To: Om Prakash Singh
  Cc: vidyas, jingoohan1, gustavo.pimentel, lorenzo.pieralisi, amurray,
	bhelgaas, kishon, thierry.reding, Jisheng.Zhang, jonathanh,
	linux-pci, linux-kernel, kthota, mmaddireddy, oop.singh

On Fri, Mar 05, 2021 at 01:42:34PM +0530, Om Prakash Singh wrote:
> PCIe EP compliance expect PTM capabilities (ROOT_CAPABLE, RES_CAPABLE,
> CLK_GRAN) to be disabled.

I guess this is just enforcing the PCIe spec requirements that only
Root Ports, RCRBs, and Switches are allowed to set the PTM Responder
Capable bit, and that the Local Clock Granularity is RsvdP if PTM Root
Capable is zero?  (PCIe r5.0, sec 7.9.16.2)

Should this be done more generally somewhere in the dwc code as
opposed to in the tegra code?

> Signed-off-by: Om Prakash Singh <omp@nvidia.com>
> ---
>  drivers/pci/controller/dwc/pcie-tegra194.c | 17 ++++++++++++++++-
>  include/uapi/linux/pci_regs.h              |  1 +
>  2 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 6fa216e..a588312 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -1639,7 +1639,7 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
>  	struct dw_pcie *pci = &pcie->pci;
>  	struct dw_pcie_ep *ep = &pci->ep;
>  	struct device *dev = pcie->dev;
> -	u32 val;
> +	u32 val, ptm_cap_base = 0;

Unnecessary init.

>  	int ret;
>  
>  	if (pcie->ep_state == EP_STATE_ENABLED)
> @@ -1760,6 +1760,21 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
>  						      PCI_CAP_ID_EXP);
>  	clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
>  
> +	/* Disable PTM root and responder capability */
> +	ptm_cap_base = dw_pcie_find_ext_capability(&pcie->pci,
> +						   PCI_EXT_CAP_ID_PTM);
> +	if (ptm_cap_base) {
> +		dw_pcie_dbi_ro_wr_en(pci);
> +		val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
> +		val &= ~PCI_PTM_CAP_ROOT;
> +		dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
> +
> +		val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
> +		val &= ~(PCI_PTM_CAP_RES | PCI_PTM_GRANULARITY_MASK);
> +		dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
> +		dw_pcie_dbi_ro_wr_dis(pci);
> +	}
> +
>  	val = (ep->msi_mem_phys & MSIX_ADDR_MATCH_LOW_OFF_MASK);
>  	val |= MSIX_ADDR_MATCH_LOW_OFF_EN;
>  	dw_pcie_writel_dbi(pci, MSIX_ADDR_MATCH_LOW_OFF, val);
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index e709ae8..9dd6f8d 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -1050,6 +1050,7 @@
>  /* Precision Time Measurement */
>  #define PCI_PTM_CAP			0x04	    /* PTM Capability */
>  #define  PCI_PTM_CAP_REQ		0x00000001  /* Requester capable */
> +#define  PCI_PTM_CAP_RES		0x00000002  /* Responder capable */
>  #define  PCI_PTM_CAP_ROOT		0x00000004  /* Root capable */
>  #define  PCI_PTM_GRANULARITY_MASK	0x0000FF00  /* Clock granularity */
>  #define PCI_PTM_CTRL			0x08	    /* PTM Control */
> -- 
> 2.7.4
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] PCI: tegra: Disable PTM capabilities for EP mode
  2021-03-05 12:19 ` Bjorn Helgaas
@ 2021-03-05 18:13   ` Vidya Sagar
  2021-03-08 10:42     ` Om Prakash Singh
  0 siblings, 1 reply; 4+ messages in thread
From: Vidya Sagar @ 2021-03-05 18:13 UTC (permalink / raw)
  To: Bjorn Helgaas, Om Prakash Singh
  Cc: jingoohan1, gustavo.pimentel, lorenzo.pieralisi, amurray,
	bhelgaas, kishon, thierry.reding, Jisheng.Zhang, jonathanh,
	linux-pci, linux-kernel, kthota, mmaddireddy, oop.singh



On 3/5/2021 5:49 PM, Bjorn Helgaas wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Fri, Mar 05, 2021 at 01:42:34PM +0530, Om Prakash Singh wrote:
>> PCIe EP compliance expect PTM capabilities (ROOT_CAPABLE, RES_CAPABLE,
>> CLK_GRAN) to be disabled.
> 
> I guess this is just enforcing the PCIe spec requirements that only
> Root Ports, RCRBs, and Switches are allowed to set the PTM Responder
> Capable bit, and that the Local Clock Granularity is RsvdP if PTM Root
> Capable is zero?  (PCIe r5.0, sec 7.9.16.2)
> 
> Should this be done more generally somewhere in the dwc code as
> opposed to in the tegra code?
Agree.

> 
>> Signed-off-by: Om Prakash Singh <omp@nvidia.com>
>> ---
>>   drivers/pci/controller/dwc/pcie-tegra194.c | 17 ++++++++++++++++-
>>   include/uapi/linux/pci_regs.h              |  1 +
>>   2 files changed, 17 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
>> index 6fa216e..a588312 100644
>> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
>> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
>> @@ -1639,7 +1639,7 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
>>        struct dw_pcie *pci = &pcie->pci;
>>        struct dw_pcie_ep *ep = &pci->ep;
>>        struct device *dev = pcie->dev;
>> -     u32 val;
>> +     u32 val, ptm_cap_base = 0;
> 
> Unnecessary init.
> 
>>        int ret;
>>
>>        if (pcie->ep_state == EP_STATE_ENABLED)
>> @@ -1760,6 +1760,21 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
>>                                                      PCI_CAP_ID_EXP);
>>        clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
>>
>> +     /* Disable PTM root and responder capability */
>> +     ptm_cap_base = dw_pcie_find_ext_capability(&pcie->pci,
>> +                                                PCI_EXT_CAP_ID_PTM);
>> +     if (ptm_cap_base) {
>> +             dw_pcie_dbi_ro_wr_en(pci);
>> +             val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
>> +             val &= ~PCI_PTM_CAP_ROOT;
>> +             dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
>> +
>> +             val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
>> +             val &= ~(PCI_PTM_CAP_RES | PCI_PTM_GRANULARITY_MASK);
Why can't this be clubbed with "val &= ~PCI_PTM_CAP_ROOT;" ?

>> +             dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
>> +             dw_pcie_dbi_ro_wr_dis(pci);
>> +     }
>> +
>>        val = (ep->msi_mem_phys & MSIX_ADDR_MATCH_LOW_OFF_MASK);
>>        val |= MSIX_ADDR_MATCH_LOW_OFF_EN;
>>        dw_pcie_writel_dbi(pci, MSIX_ADDR_MATCH_LOW_OFF, val);
>> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
>> index e709ae8..9dd6f8d 100644
>> --- a/include/uapi/linux/pci_regs.h
>> +++ b/include/uapi/linux/pci_regs.h
>> @@ -1050,6 +1050,7 @@
>>   /* Precision Time Measurement */
>>   #define PCI_PTM_CAP                  0x04        /* PTM Capability */
>>   #define  PCI_PTM_CAP_REQ             0x00000001  /* Requester capable */
>> +#define  PCI_PTM_CAP_RES             0x00000002  /* Responder capable */
>>   #define  PCI_PTM_CAP_ROOT            0x00000004  /* Root capable */
>>   #define  PCI_PTM_GRANULARITY_MASK    0x0000FF00  /* Clock granularity */
>>   #define PCI_PTM_CTRL                 0x08        /* PTM Control */
>> --
>> 2.7.4
>>

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] PCI: tegra: Disable PTM capabilities for EP mode
  2021-03-05 18:13   ` Vidya Sagar
@ 2021-03-08 10:42     ` Om Prakash Singh
  0 siblings, 0 replies; 4+ messages in thread
From: Om Prakash Singh @ 2021-03-08 10:42 UTC (permalink / raw)
  To: Vidya Sagar, Bjorn Helgaas
  Cc: jingoohan1, gustavo.pimentel, lorenzo.pieralisi, amurray,
	bhelgaas, kishon, thierry.reding, Jisheng.Zhang, jonathanh,
	linux-pci, linux-kernel, kthota, mmaddireddy, oop.singh

On 3/5/2021 11:43 PM, Vidya Sagar wrote:
> 
> 
> On 3/5/2021 5:49 PM, Bjorn Helgaas wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> On Fri, Mar 05, 2021 at 01:42:34PM +0530, Om Prakash Singh wrote:
>>> PCIe EP compliance expect PTM capabilities (ROOT_CAPABLE, RES_CAPABLE,
>>> CLK_GRAN) to be disabled.
>>
>> I guess this is just enforcing the PCIe spec requirements that only
>> Root Ports, RCRBs, and Switches are allowed to set the PTM Responder
>> Capable bit, and that the Local Clock Granularity is RsvdP if PTM Root
>> Capable is zero?  (PCIe r5.0, sec 7.9.16.2)
>>
>> Should this be done more generally somewhere in the dwc code as
>> opposed to in the tegra code?
> Agree.
>
I'll take care of this in next patch version
 
>>
>>> Signed-off-by: Om Prakash Singh <omp@nvidia.com>
>>> ---
>>>   drivers/pci/controller/dwc/pcie-tegra194.c | 17 ++++++++++++++++-
>>>   include/uapi/linux/pci_regs.h              |  1 +
>>>   2 files changed, 17 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
>>> index 6fa216e..a588312 100644
>>> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
>>> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
>>> @@ -1639,7 +1639,7 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
>>>        struct dw_pcie *pci = &pcie->pci;
>>>        struct dw_pcie_ep *ep = &pci->ep;
>>>        struct device *dev = pcie->dev;
>>> -     u32 val;
>>> +     u32 val, ptm_cap_base = 0;
>>
>> Unnecessary init.
>>
>>>        int ret;
>>>
>>>        if (pcie->ep_state == EP_STATE_ENABLED)
>>> @@ -1760,6 +1760,21 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
>>>                                                      PCI_CAP_ID_EXP);
>>>        clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
>>>
>>> +     /* Disable PTM root and responder capability */
>>> +     ptm_cap_base = dw_pcie_find_ext_capability(&pcie->pci,
>>> +                                                PCI_EXT_CAP_ID_PTM);
>>> +     if (ptm_cap_base) {
>>> +             dw_pcie_dbi_ro_wr_en(pci);
>>> +             val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
>>> +             val &= ~PCI_PTM_CAP_ROOT;
>>> +             dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
>>> +
>>> +             val = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
>>> +             val &= ~(PCI_PTM_CAP_RES | PCI_PTM_GRANULARITY_MASK);
> Why can't this be clubbed with "val &= ~PCI_PTM_CAP_ROOT;" ?
>
This cannot be clubbed as PTM root capability needs to disable first before disabling responded capability 
 
>>> +             dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, val);
>>> +             dw_pcie_dbi_ro_wr_dis(pci);
>>> +     }
>>> +
>>>        val = (ep->msi_mem_phys & MSIX_ADDR_MATCH_LOW_OFF_MASK);
>>>        val |= MSIX_ADDR_MATCH_LOW_OFF_EN;
>>>        dw_pcie_writel_dbi(pci, MSIX_ADDR_MATCH_LOW_OFF, val);
>>> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
>>> index e709ae8..9dd6f8d 100644
>>> --- a/include/uapi/linux/pci_regs.h
>>> +++ b/include/uapi/linux/pci_regs.h
>>> @@ -1050,6 +1050,7 @@
>>>   /* Precision Time Measurement */
>>>   #define PCI_PTM_CAP                  0x04        /* PTM Capability */
>>>   #define  PCI_PTM_CAP_REQ             0x00000001  /* Requester capable */
>>> +#define  PCI_PTM_CAP_RES             0x00000002  /* Responder capable */
>>>   #define  PCI_PTM_CAP_ROOT            0x00000004  /* Root capable */
>>>   #define  PCI_PTM_GRANULARITY_MASK    0x0000FF00  /* Clock granularity */
>>>   #define PCI_PTM_CTRL                 0x08        /* PTM Control */
>>> -- 
>>> 2.7.4
>>>


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-03-08 10:43 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-05  8:12 [PATCH] PCI: tegra: Disable PTM capabilities for EP mode Om Prakash Singh
2021-03-05 12:19 ` Bjorn Helgaas
2021-03-05 18:13   ` Vidya Sagar
2021-03-08 10:42     ` Om Prakash Singh

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