On Sat, Feb 22, 2025 at 10:33:35PM +0800, Hans Zhang wrote: > Add the debugfs property to provide a view of the current link's LTSSM > status from the root port device. > > /sys/kernel/debug/dwc_pcie_<dev>/ltssm_status > > Signed-off-by: Hans Zhang <18255117159@xxxxxxx> Just minor comments below. > Tested-by: Niklas Cassel <cassel@xxxxxxxxxx> > --- > Changes since v3: > https://lore.kernel.org/linux-pci/20250214144618.176028-1-18255117159@xxxxxxx/ > > - My v4 patch is updated to the latest based on Shradha's v7 patch. > - Submissions based on the following v7 patches: > https://patchwork.kernel.org/project/linux-pci/patch/20250221131548.59616-2-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250221131548.59616-3-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250221131548.59616-4-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250221131548.59616-5-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250221131548.59616-6-shradha.t@xxxxxxxxxxx/ > > Changes since v2: > https://lore.kernel.org/linux-pci/20250206151343.26779-1-18255117159@xxxxxxx/ > > - Git pulls the latest code and fixes conflicts. > - Do not place into sysfs node as recommended by maintainer. Shradha-based patch > is put into debugfs. > - Submissions based on the following v6 patches: > https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-2-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-3-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-4-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-5-shradha.t@xxxxxxxxxxx/ > > Changes since v1: > https://lore.kernel.org/linux-pci/20250123071326.1810751-1-18255117159@xxxxxxx/ > > - Do not place into sysfs node as recommended by maintainer. Shradha-based patch > is put into debugfs. > - Submissions based on the following v5 patches: > https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-2-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-3-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-4-shradha.t@xxxxxxxxxxx/ > https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-5-shradha.t@xxxxxxxxxxx/ > --- > Documentation/ABI/testing/debugfs-dwc-pcie | 6 +++ > .../controller/dwc/pcie-designware-debugfs.c | 29 +++++++++++ > .../pci/controller/dwc/pcie-designware-host.c | 50 +++++++++++++++++++ > drivers/pci/controller/dwc/pcie-designware.h | 33 ++++++++++++ > 4 files changed, 118 insertions(+) > > diff --git a/Documentation/ABI/testing/debugfs-dwc-pcie b/Documentation/ABI/testing/debugfs-dwc-pcie > index 650a89b0511e..86418f7ed4b5 100644 > --- a/Documentation/ABI/testing/debugfs-dwc-pcie > +++ b/Documentation/ABI/testing/debugfs-dwc-pcie > @@ -142,3 +142,9 @@ Description: (RW) Some lanes in the event list are lane specific events. These i > events 1) - 11) and 34) - 35). > Write lane number for which counter needs to be enabled/disabled/dumped. > Read will return the current selected lane number. Lane0 is selected by default. > + > +What: /sys/kernel/debug/dwc_pcie_<dev>/ltssm_status > +Date: February 2025 > +Contact: Hans Zhang <18255117159@xxxxxxx> > +Description: (RO) Read will return the current value of the PCIe link status raw value and > + string status. 'Read will return the current PCIe LTSSM state in both string and raw value.' > diff --git a/drivers/pci/controller/dwc/pcie-designware-debugfs.c b/drivers/pci/controller/dwc/pcie-designware-debugfs.c > index dca1e9999113..39487bd184e1 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-debugfs.c > +++ b/drivers/pci/controller/dwc/pcie-designware-debugfs.c > @@ -533,6 +533,33 @@ static int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci, struct dentry *dir) > return ret; > } > > +static int dwc_pcie_ltssm_status_show(struct seq_file *s, void *v) > +{ > + struct dw_pcie *pci = s->private; > + enum dw_pcie_ltssm val; > + > + val = dw_pcie_get_ltssm(pci); > + seq_printf(s, "%s (0x%02x)\n", dw_ltssm_sts_string(val), val); > + > + return 0; > +} > + > +static int dwc_pcie_ltssm_status_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, dwc_pcie_ltssm_status_show, inode->i_private); > +} > + > +static const struct file_operations dwc_pcie_ltssm_status_ops = { > + .open = dwc_pcie_ltssm_status_open, > + .read = seq_read, > +}; > + > +static void dwc_pcie_ltssm_debugfs_init(struct dw_pcie *pci, struct dentry *dir) > +{ > + debugfs_create_file("ltssm_status", 0444, dir, pci, > + &dwc_pcie_ltssm_status_ops); > +} > + > void dwc_pcie_debugfs_deinit(struct dw_pcie *pci) > { > dwc_pcie_rasdes_debugfs_deinit(pci); > @@ -560,5 +587,7 @@ int dwc_pcie_debugfs_init(struct dw_pcie *pci) > if (ret) > dev_dbg(dev, "RASDES debugfs init failed\n"); > > + dwc_pcie_ltssm_debugfs_init(pci, dir); > + > return 0; > } > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c > index 2081e8c72d12..46182e97659e 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-host.c > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c > @@ -418,6 +418,56 @@ static void dw_pcie_host_request_msg_tlp_res(struct dw_pcie_rp *pp) > } > } > > +char *dw_ltssm_sts_string(enum dw_pcie_ltssm ltssm) const char *dw_pcie_ltssm_string() > +{ > + char *str; const char * > + > + switch (ltssm) { > +#define DW_PCIE_LTSSM_NAME(n) case n: str = #n; break > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DETECT_QUIET); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DETECT_ACT); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_POLL_ACTIVE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_POLL_COMPLIANCE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_POLL_CONFIG); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_PRE_DETECT_QUIET); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DETECT_WAIT); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LINKWD_START); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LINKWD_ACEPT); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LANENUM_WAI); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LANENUM_ACEPT); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_COMPLETE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_IDLE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_LOCK); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_SPEED); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_RCVRCFG); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_IDLE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L0); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L0S); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L123_SEND_EIDLE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L1_IDLE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L2_IDLE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L2_WAKE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DISABLED_ENTRY); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DISABLED_IDLE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DISABLED); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_ENTRY); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_ACTIVE); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_EXIT); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_EXIT_TIMEOUT); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_HOT_RESET_ENTRY); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_HOT_RESET); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ0); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ1); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ2); > + DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ3); > + default: > + str = "DW_PCIE_LTSSM_UNKNOWN"; > + break; > + } > + > + return str + strlen("DW_PCIE_LTSSM_"); > +} > + > int dw_pcie_host_init(struct dw_pcie_rp *pp) > { > struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > index 7f9807d4e5de..65ff271eaabc 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -330,9 +330,40 @@ enum dw_pcie_ltssm { > /* Need to align with PCIE_PORT_DEBUG0 bits 0:5 */ > DW_PCIE_LTSSM_DETECT_QUIET = 0x0, > DW_PCIE_LTSSM_DETECT_ACT = 0x1, > + DW_PCIE_LTSSM_POLL_ACTIVE = 0x2, > + DW_PCIE_LTSSM_POLL_COMPLIANCE = 0x3, > + DW_PCIE_LTSSM_POLL_CONFIG = 0x4, > + DW_PCIE_LTSSM_PRE_DETECT_QUIET = 0x5, > DW_PCIE_LTSSM_DETECT_WAIT = 0x6, > + DW_PCIE_LTSSM_CFG_LINKWD_START = 0x7, > + DW_PCIE_LTSSM_CFG_LINKWD_ACEPT = 0x8, > + DW_PCIE_LTSSM_CFG_LANENUM_WAI = 0x9, > + DW_PCIE_LTSSM_CFG_LANENUM_ACEPT = 0xa, > + DW_PCIE_LTSSM_CFG_COMPLETE = 0xb, > + DW_PCIE_LTSSM_CFG_IDLE = 0xc, > + DW_PCIE_LTSSM_RCVRY_LOCK = 0xd, > + DW_PCIE_LTSSM_RCVRY_SPEED = 0xe, > + DW_PCIE_LTSSM_RCVRY_RCVRCFG = 0xf, > + DW_PCIE_LTSSM_RCVRY_IDLE = 0x10, > DW_PCIE_LTSSM_L0 = 0x11, > + DW_PCIE_LTSSM_L0S = 0x12, > + DW_PCIE_LTSSM_L123_SEND_EIDLE = 0x13, > + DW_PCIE_LTSSM_L1_IDLE = 0x14, > DW_PCIE_LTSSM_L2_IDLE = 0x15, > + DW_PCIE_LTSSM_L2_WAKE = 0x16, > + DW_PCIE_LTSSM_DISABLED_ENTRY = 0x17, > + DW_PCIE_LTSSM_DISABLED_IDLE = 0x18, > + DW_PCIE_LTSSM_DISABLED = 0x19, > + DW_PCIE_LTSSM_LPBK_ENTRY = 0x1a, > + DW_PCIE_LTSSM_LPBK_ACTIVE = 0x1b, > + DW_PCIE_LTSSM_LPBK_EXIT = 0x1c, > + DW_PCIE_LTSSM_LPBK_EXIT_TIMEOUT = 0x1d, > + DW_PCIE_LTSSM_HOT_RESET_ENTRY = 0x1e, > + DW_PCIE_LTSSM_HOT_RESET = 0x1f, > + DW_PCIE_LTSSM_RCVRY_EQ0 = 0x20, > + DW_PCIE_LTSSM_RCVRY_EQ1 = 0x21, > + DW_PCIE_LTSSM_RCVRY_EQ2 = 0x22, > + DW_PCIE_LTSSM_RCVRY_EQ3 = 0x23, > > DW_PCIE_LTSSM_UNKNOWN = 0xFFFFFFFF, > }; > @@ -683,6 +714,8 @@ static inline enum dw_pcie_ltssm dw_pcie_get_ltssm(struct dw_pcie *pci) > return (enum dw_pcie_ltssm)FIELD_GET(PORT_LOGIC_LTSSM_STATE_MASK, val); > } > > +char *dw_ltssm_sts_string(enum dw_pcie_ltssm ltssm); const char *dw_pcie_ltssm_string() - Mani -- மணிவண்ணன் சதாசிவம்
