On Tue, Jan 25, 2022 at 10:51:00AM +0200, Mathias Nyman wrote: > On 24.1.2022 18.46, Peter Zijlstra wrote: > > FYI, I'm thinking early_xdbc_parse_parameter should've now given > > dpgp_num: 1 ? > > > > Yes, it should. > > Looks like there's a parsing issue. > "earlyprintk=xdbc1,keep" fails on our Tigerlake as well. > > Without the "keep" option it works for me: > > [ 0.000000] Command line: console=ttyS0,115200n8 buildroot_hostname=tgl04 earlyprintk=xdbc1 dmi_entry_point=0x74374000 > [ 0.000000] xhci_dbc:early_xdbc_parse_parameter: dbgp_num: 1 [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.16.0+ root=UUID=a652986c-fbc6-4341-85c3-b4ad4402f130 ro debug ignore_loglevel sysrq_always_enabled usbcore.autosuspend=-1 earlyprintk=xdbc1,keep force_early_printk sched_verbose ft race=nop mitigations=off nokaslr [ 0.000000] xhci_dbc:early_xdbc_parse_parameter: dbgp_num: 1 [ 0.399988] xhci_dbc:xdbc_start: DbC is running now, control 0x8d000003 port ID 15 [ 0.399998] xhci_dbc:xdbc_handle_port_status: connect status change event [ 0.399999] xhci_dbc:xdbc_handle_port_status: port reset change event [ 0.431217] printk: console [earlyxdbc0] enabled Success!! I'll go submit proper patches for this then. --- diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index d3c531d3b244..68b38925a74f 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -387,7 +387,7 @@ static int __init setup_early_printk(char *buf) #endif #ifdef CONFIG_EARLY_PRINTK_USB_XDBC if (!strncmp(buf, "xdbc", 4)) - early_xdbc_parse_parameter(buf + 4); + early_xdbc_parse_parameter(buf + 4, keep); #endif buf++; diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index a698196377be..9bf3872895ab 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1505,6 +1505,7 @@ void __init tsc_early_init(void) loops_per_jiffy = get_loops_per_jiffy(); tsc_enable_sched_clock(); + use_tsc_delay(); } void __init tsc_init(void) diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index 4502108069cd..a40db9618e8e 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -29,11 +29,15 @@ static struct xdbc_state xdbc; static bool early_console_keep; +#if 0 #ifdef XDBC_TRACE #define xdbc_trace trace_printk #else static inline void xdbc_trace(const char *fmt, ...) { } #endif /* XDBC_TRACE */ +#else +#define xdbc_trace pr_err +#endif static void __iomem * __init xdbc_map_pci_mmio(u32 bus, u32 dev, u32 func) { @@ -417,9 +421,11 @@ static void xdbc_ring_doorbell(int target) static int xdbc_start(void) { + bool first_try = true; u32 ctrl, status; int ret; +retry: ctrl = readl(&xdbc.xdbc_reg->control); writel(ctrl | CTRL_DBC_ENABLE | CTRL_PORT_ENABLE, &xdbc.xdbc_reg->control); ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, CTRL_DBC_ENABLE, 100000, 100); @@ -429,13 +435,21 @@ static int xdbc_start(void) } /* Reset port to avoid bus hang: */ - if (xdbc.vendor == PCI_VENDOR_ID_INTEL) + if (xdbc.vendor == PCI_VENDOR_ID_INTEL && first_try) xdbc_reset_debug_port(); /* Wait for port connection: */ ret = handshake(&xdbc.xdbc_reg->portsc, PORTSC_CONN_STATUS, PORTSC_CONN_STATUS, 5000000, 100); if (ret) { - xdbc_trace("waiting for connection timed out\n"); + xdbc_trace("waiting for connection timed out, DCPORTSC:0x%x\n", + readl(&xdbc.xdbc_reg->portsc)); + if (first_try) { + first_try = false; + /* Toggle DCE and retry without port reset */ + writel(0, &xdbc.xdbc_reg->control); + handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10); + goto retry; + } return ret; } @@ -599,23 +631,26 @@ static int __init xdbc_early_setup(void) return 0; } -int __init early_xdbc_parse_parameter(char *s) +int __init early_xdbc_parse_parameter(char *s, int keep_early) { unsigned long dbgp_num = 0; u32 bus, dev, func, offset; + char *e; int ret; if (!early_pci_allowed()) return -EPERM; - if (strstr(s, "keep")) - early_console_keep = true; + early_console_keep = keep_early; if (xdbc.xdbc_reg) return 0; - if (*s && kstrtoul(s, 0, &dbgp_num)) - dbgp_num = 0; + if (*s) { + dbgp_num = simple_strtoul(s, &e, 10); + if (s == e) + dbgp_num = 0; + } pr_notice("dbgp_num: %lu\n", dbgp_num); diff --git a/include/linux/usb/xhci-dbgp.h b/include/linux/usb/xhci-dbgp.h index 0a37f1283bf0..01fe768873f9 100644 --- a/include/linux/usb/xhci-dbgp.h +++ b/include/linux/usb/xhci-dbgp.h @@ -15,7 +15,7 @@ #define __LINUX_XHCI_DBGP_H #ifdef CONFIG_EARLY_PRINTK_USB_XDBC -int __init early_xdbc_parse_parameter(char *s); +int __init early_xdbc_parse_parameter(char *s, int keep_early); int __init early_xdbc_setup_hardware(void); void __init early_xdbc_register_console(void); #else