重庆网站关键词排名优化,网站怎么做百度能搜到,新手怎么做电商运营,软件项目管理总结The USB peripheral detects the lack of 3 consecutive SOF packets as a suspend request from the USB host. 1 驱动shutdown顺序 系统关机或重启的过程中#xff0c;会调用设备驱动的shutdown函数来完成设备的关闭操作#xff0c;有需要的设备可以在驱动中定义该函数。其…The USB peripheral detects the lack of 3 consecutive SOF packets as a suspend request from the USB host. 1 驱动shutdown顺序 系统关机或重启的过程中会调用设备驱动的shutdown函数来完成设备的关闭操作有需要的设备可以在驱动中定义该函数。其调用流程如下 kernel_restart kernel_restart_prepare device_shutdown // 逆向遍历devices_kset-list所有device dev-driver-shutdown 由此可见各个驱动shutdown的顺序由设备在链表中的位置决定后添加的先调用。设备添加到链表中的流程如下 device_initialize device_add kobject_add kobj_kset_join list_add_tail(kobj-entry, kobj-kset-list) 由此可见设备注册时会把节点添加到devices_kset-list末尾。因此驱动的shutdown顺序是设备注册的逆序而在通过dts创建设备的系统中设备的注册顺序是设备节点在dts中的前后顺序。 2 USB主机PORTSC寄存器 2.1 EHCI Connected: PORTSC1.CCS (bit 0) - Current Connection Status PORTSC1.CSC (bit 1) - Connection Status Change Reset - Great Than 10ms: PORTSC1.PR (bit 8) - Port Reset PORTSC1.PE (bit 2) - Port Enable Disconnected: PORTSC1.CCS (bit 0) PORTSC1.CSC (bit 1) PORTSC1.PEC(bit 3) - Port Enable Change 2.2 xHCI Connected: PORTSC.CCS (bit0 ) - Current Connection Status Reset - Great Than 10ms: PORTSC.PR (bit4) - Port Reset PORTSC.PED (bit1) - Port Enabled/Disabled echo file xhci-hub.c p /d/dynamic_debug/control dmesg -n4 wPortStatus 0x03表示复位成功 3 EHCI电源管理 3.1 休眠唤醒流程 suspend usb_device时先suspend usb interface再挂起整个设备也就是调用generic.c类似于Windows CCGP驱动的generic_suspend() resume usb_device时先唤醒整个设备也就是调用generic.c类似于Windows CCGP驱动的generic_resume()再resume usb interface。 3.2 LS/FS/HS Early Suspend Interrupt DWC2 databook indicates if the core sets ErlySusp bit, an idle state has been detected on the USB for 3 ms. This situation can be occurred when waiting a request from user daemon. So, we should keep the connection between udc and gadget even though this interrupt is occurred. 3.3 External Hub reset-resume Issue hub_port_connect_change() usb_detect_quirks(), which will set“udev-persist_enabled 1” hub_activate(), which checks“udev-persist_enabled 1”, then sets “udev-reset_resume 1; ”the“reset_resume”flag will cause EHCI stack calls usb_port_resume() to reset the external hub when the system exits suspend-to-RAM. 3.4 HS Device Suspend和Resume Suspend 1高速设备在收到挂起信号3ms空闲后应在0.125ms内切换到全速状态也就是说要把下拉终端电阻45Ω移除并在D数据线上重新挂上1.5k上拉电阻。 2设备在随后的100-875μs内检测数据线上的状态。如果该状态是一个Full speed J那么说明host发下来的是一个挂起信号如果此时该状态是SE0说明是host drive数据线D/D-到0这是一个复位信号复位信号会持续至少10ms时间。 Resume 因为设备挂起时处于全速状态当host需要设备退出suspend状态时先发送一个持续时间超过20ms的Fulll Speed K状态设备看到K状态结束的1.3us持续2个 LS bit位时间内醒过来而host需要在3ms内发送uSOF信号以维持正常的高速信号模式否则设备又将进入suspend。 4 xHCI电源管理 4.1 Gadget Runtime-PM APIs include/linux/usb/gadget.h static inline int usb_gadget_autopm_get(struct usb_gadget *gadget); static inline void usb_gadget_autopm_put(struct usb_gadget *gadget); 4.2 HS LPM L0means ON L1means SLEEP L2traditional USB 2.0 suspend L3means OFF 4.3 SS LPM U0: normal work U1/U2: 一般都不支持的Linux DT直接禁止了因为绝大部分的USB3的U1/U2都是有问题的。 U3: suspend 4.4 USB3 Resume 1LTSSM处于U3状态 2PHY收到LFPS WAKEUP信号通知Link层LTSSMLTSSM指导PHY也发送LFPS给对端设备 3LTSSM进入Recovery状态包括TS1TS2IDLE训练 4持续发送TS1直到成功接收到对端发送的8个TS1然后进入TS2阶段在TS2阶段需要接收到对端发送的至少8个TS2并且自己给对端至少也发送了16个TS2此时TS1TS2训练成功 5确认TS1和TS2训练是否成功如果TS1和TS2都成功转入下一步否则如果TS1或者TS2训练失败转入SS.Inactive 6LTSSM指导PHY进行IDLE训练接收到对端发送的至少8个空闲符号时确保自己也同时至少发送了16个IDLE符号给对端 7确认上一步是否成功如果成功转入U0否则转入SS.Inactive。 注意 LFPS和IDLE都是PIPEPHY Interface for PCI Express接口PHY实施的 而TS1TS2训练序列是LTSSM生成的数据 LGOOD_0 to LGOOD_7的发送表示Link层已成功收到对端发送的数据(CRC校验正确) LCRD_A to LCRD_DCRD means Credit的发送表示Link层已成功将接收的数据push入protocol层说明Link层LCRD_X对应的buffer可用了USB3协议实施时Link层最多可缓存接收到的4个packets。 4.5 全局禁止运行时autosuspend echo -1 /sys/module/usbcore/parameters/autosuspend 4.6 autosuspend Intel APL (Gen9, A39X0) 8-port MPH xHCI会注册2个host一个是usb1LS/FS/HS另一个是usb2SS。 禁止usb1电源管理 echo on /sys/bus/usb/devices/usb1/power/control 禁止usb2电源管理 echo on /sys/bus/usb/devices/usb2/power/control 5 Abbreviations ARCArgonant RISC Core CCGPWindows USB Common Class Generic ParentLinux内核类似的驱动就是usb_generic_drivergeneric.c CCGP MI_Common Class Generic Parent Multi Interface DWC2Design Ware Controller 2Apple的嵌入式设备包括iPad和iPhone都是使用的DWC2 ISP1161Philips Integrated host Solution Pairs 1161“Firms introduce USB host controllers”https://www.eetimes.com/document.asp?doc_id1290054 MDATAMore DATAUSB双缓冲ep_kind配置使能切换机制对应到DATA0和DATA1 Quirksthe attributes of a device that are considered to be noncompliant with expected operation SL811HSCypress/ScanLogic 811 Host/Slave性能上与ISP1161Integrated host Solution Pairs 1161相当 TDITransDimension Inc.该公司首先发明了将TT集成到EHCI RootHub中的方法这样对于嵌入式系统来说就省去了OHCI/UHCI的硬件同时降低了成本作为对该公司的纪念Linux内核定义了宏ehci_is_TDI(ehci)产品UHC124表示USB Host Controller收购了ARC USB技术现已被chipidea收购chipidea又被mips收购 TTTransaction Translator事务转换器将USB2.0的包转换成USB1.1的包 USB BH resetBigger Hammer or Brad Hosler表示warm resetyou may be confused why the USB 3.0 spec calls the same type of reset warm reset in some places and BH reset in other places. BH reset is supposed to stand for Big Hammer reset, but it also stands for Brad Hosler. Brad died shortly after the USB 3.0 bus specification was started, and they decided to name the reset after him. The suggestion was made shortly before the spec was finalized, so the wording is a bit inconsistent. USB Host枚举时-71错误码可能原因DP和DM走线太长导致眼图差DP和DM接反了 USB KVMKVM是键盘(Keyboard)、显示器(Video)、鼠标(Mouse)的缩写KVM端口是25-pin包含VGA接口和USB接口 uSOFmicro Start of Frame125us
