Re: [PATCH] PCI: dwc: Add PCIe event counters for groups 5 to 7 in DWC debugfs

[Hans Zhang]

On 3/7/26 00:11, Shawn Lin wrote:
> 在 2026/03/06 星期五 23:07, Hans Zhang 写道:
> > Extend the DesignWare PCIe controller's debugfs statistical counter
> > interface with event definitions from groups 5 through 7 as documented
> > in the DWC PCIe Databook (version 3.30a, section 3.8.2.3, Tables 3-59,
> > 3-60, 3-61). These counters provide visibility into Layer1 non-error
> > events (link state transitions,ASPM, L1 substates), Layer2 DLLP
> > exchanges, and Layer3 TLP transactions.
> >
> > The counters are exposed under the debugfs statistical counter directory,
> > allowing users to monitor link behavior and diagnose PCIe protocol issues
> > more effectively.
> >
> > Co-developed-by: Cheng Xin <chengqin1525@xxxxxxx>
> > Signed-off-by: Cheng Xin <chengqin1525@xxxxxxx>
> > Signed-off-by: Hans Zhang <18255117159@xxxxxxx>
> > ---
> > Thank you, Cheng Xin, for providing the 3.30a version of the DWC PCIe 
> > Data Book.
> > ---
> >   .../controller/dwc/pcie-designware-debugfs.c  | 52 ++++++++++++++++++-
> >   1 file changed, 51 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-debugfs.c b/ 
> > drivers/pci/controller/dwc/pcie-designware-debugfs.c
> > index 0d1340c9b364..2efddb21b2b2 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-debugfs.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-debugfs.c
> > @@ -131,13 +131,16 @@ static const u32 err_inj_type_mask[] = {
> >    *                   supported in DWC RAS DES
> >    * @name: Name of the error counter
> >    * @group_no: Group number that the event belongs to. The value can 
> > range
> > - *          from 0 to 4
> > + *          from 0 to 7
> >    * @event_no: Event number of the particular event. The value ranges 
> > are:
> >    *        Group 0: 0 - 10
> >    *        Group 1: 5 - 13
> >    *        Group 2: 0 - 7
> >    *        Group 3: 0 - 5
> >    *        Group 4: 0 - 1
> > + *        Group 5: 0 - 13
> > + *        Group 6: 0 - 6
> > + *        Group 7: 0 - 25
> >    */
> >   struct dwc_pcie_event_counter {
> >       const char *name;
> > @@ -181,6 +184,53 @@ static const struct dwc_pcie_event_counter 
> > event_list[] = {
> >       {"completion_timeout", 0x3, 0x5},
> >       {"ebuf_skp_add", 0x4, 0x0},
> >       {"ebuf_skp_del", 0x4, 0x1},
> > +    {"l0_to_recovery_entry", 0x5, 0x0},
> > +    {"l1_to_recovery_entry", 0x5, 0x1},
> > +    {"tx_l0s_entry", 0x5, 0x2},
> > +    {"rx_l0s_entry", 0x5, 0x3},
> > +    {"aspm_l1_reject", 0x5, 0x4},
> > +    {"l1_entry", 0x5, 0x5},
> > +    {"l1_cpm", 0x5, 0x6},
> > +    {"l1.1_entry", 0x5, 0x7},
> > +    {"l1.2_entry", 0x5, 0x8},
> > +    {"l1_short_duration", 0x5, 0x9},
> > +    {"l1.2_abort", 0x5, 0xa},
> > +    {"l2_entry", 0x5, 0xb},
> > +    {"speed_change", 0x5, 0xc},
> > +    {"link_width_change", 0x5, 0xd},
> > +    {"tx_ack_dllp", 0x6, 0x0},
> > +    {"tx_update_fc_dllp", 0x6, 0x1},
> > +    {"rx_ack_dllp", 0x6, 0x2},
> > +    {"rx_update_fc_dllp", 0x6, 0x3},
> > +    {"rx_nullified_tlp", 0x6, 0x4},
> > +    {"tx_nullified_tlp", 0x6, 0x5},
> > +    {"rx_duplicate_tlp", 0x6, 0x6},
> > +    {"tx_memory_write", 0x7, 0x0},
> > +    {"tx_memory_read", 0x7, 0x1},
> > +    {"tx_configuration_write", 0x7, 0x2},
> > +    {"tx_configuration_read", 0x7, 0x3},
> > +    {"tx_io_write", 0x7, 0x4},
> > +    {"tx_io_read", 0x7, 0x5},
> > +    {"tx_completion_without_data", 0x7, 0x6},
> > +    {"tx_completion_w_data", 0x7, 0x7},
> > +    {"tx_message_tlp_pcie_vc_only", 0x7, 0x8},
> > +    {"tx_atomic", 0x7, 0x9},
> > +    {"tx_tlp_with_prefix", 0x7, 0xa},
> > +    {"rx_memory_write", 0x7, 0xb},
> > +    {"rx_memory_read", 0x7, 0xc},
> > +    {"rx_configuration_write", 0x7, 0xd},
> > +    {"rx_configuration_read", 0x7, 0xe},
> > +    {"rx_io_write", 0x7, 0xf},
> > +    {"rx_io_read", 0x7, 0x10},
> > +    {"rx_completion_without_data", 0x7, 0x11},
> > +    {"rx_completion_w_data", 0x7, 0x12},
> > +    {"rx_message_tlp_pcie_vc_only", 0x7, 0x13},
> > +    {"rx_atomic", 0x7, 0x14},
> > +    {"rx_tlp_with_prefix", 0x7, 0x15},
>
> Hmm, 5.10a/5.60a databooks only list the first 21 events for Group 7,
> It's rather counterintuitive, perhaps it would make sense that debug 
> signals should keep adding more. Other parts look good to me.

Hi Shawn,

Thank you very much for your reply and reminder.

The version information in the commit message is incorrect. It should be 
"6.30a" instead of "3.30a". I will send the next version with corrections.

Best regards,
Hans

> > +    {"tx_ccix_tlp", 0x7, 0x16},
> > +    {"rx_ccix_tlp", 0x7, 0x17},
> > +    {"tx_deferrable_memory_write_tlp", 0x7, 0x18},
> > +    {"rx_deferrable_memory_write_tlp", 0x7, 0x19},
> >   };
> >   static ssize_t lane_detect_read(struct file *file, char __user *buf,