On Mon, 10 Jul 2017, Alan Robertson wrote: > On Sat, Jul 8, 2017 at 5:26 PM, Alan Robertson <clinicalitltd@xxxxxxxxx> wrote: > > On Sat, Jul 8, 2017 at 4:52 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > >> On Sat, 8 Jul 2017, Alan Robertson wrote: > >> > >>> On Sat, Jul 8, 2017 at 2:04 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > >>> > On Fri, 7 Jul 2017, Alan Robertson wrote: > >>> > > >>> >> Sorry to return to this topic & appreciate it might be either specific > >>> >> to either the Pi or the system(s) I'm connecting it to, but have now > >>> >> had time to try a few more combinations out and would appreciate any > >>> >> thoughts from the experts here. > >>> >> > >>> >> To give some extra background - I've got the Pi configured to > >>> >> automatically overwrite the mass storage device filestore upon boot, > >>> >> so it is always presenting a fresh filesystem. Each system below is > >>> >> made by a different manufacturer and is a closed system, so I have no > >>> >> ability to perform any diagnostics at that end. > >>> >> > >>> >> System 1 - Always works > >>> >> System 2 - Shows no USB stick connected > >>> >> System 3 - Gives error when trying to save (memory error) > >>> >> System 4 - Says unidentified USB > >>> >> (Windows PC - Always works) > >>> >> (Linux PC - Always works) > >>> >> > >>> >> At first I thought this was due to minor subtleties of how the > >>> >> g_mass_storage device was being presented as a standard Sandisk USB > >>> >> memory stick works fine in all systems. > >>> >> > >>> >> However I then started to notice some unusual behaviour, if rather > >>> >> than doing a reboot (and wiping it fresh), I kept the power running > >>> >> and moved it between machines. > >>> >> > >>> >> If I started with System 1 first, then systems 2, 3, 4 would all > >>> >> recognise/write to it OK. ... > OK I've had another play about with things this afternoon and > annotated the dmesg outputs to describe what I was doing at each > point. > > I haven't yet tried to recompile the kernel as that seems a slightly > slow process on the Pi (due to processing speed) and it make take me a > few goes to get it right - I thought I'd just check back initially in > case these logs provide sufficient clues! Obviously if not then I'll > look into that more. > > The key bit to my untrained eye seemed to be that until the line > 'g_mass_storage gadget: high-speed config #1: Linux File-Backed > Storage' appears, the Pi is unreadable by Systems 2-4. After that has > appeared in then appears to be readable, even though when connecting > to System 2 it (understandably and correctly) shows as low-speed > instead. Stop/start g_mass_storage doesn't appear to make a > difference. I agree. In fact, your logs seem to indicate pretty clearly that the problem doesn't lie in g_mass_storage at all, but rather in the dwc2 USB Device Controller driver. I have CC'ed the maintainer of the dwc2 driver. Here's the first log: > [ 15.891896] Mass Storage Function, version: 2009/09/11 > [ 15.891929] LUN: removable file: (no medium) > [ 15.892120] LUN: removable file: /home/pi/piusb.bin > [ 15.892135] Number of LUNs=1 > [ 15.894168] g_mass_storage gadget: Mass Storage Gadget, version: 2009/09/11 > [ 15.894200] g_mass_storage gadget: g_mass_storage ready > [ 15.894245] dwc2 20980000.usb: dwc2_hsotg_enqueue_setup: failed queue (-11) > [ 15.897276] dwc2 20980000.usb: bound driver g_mass_storage > CONNECTED TO SYSTEM 2 > [ 263.798965] dwc2 20980000.usb: new device is low-speed > [ 269.497623] dwc2 20980000.usb: new device is low-speed > [ 275.115548] dwc2 20980000.usb: new device is low-speed > STILL NOT SHOWING UP ON SYSTEM 2 SO UNPLUGGED > (no extra message) Connecting at low speed is definitely a bug. The UDC driver should have connected at full speed. (It's possible that the log message is wrong, and the device really did connect at full speed. But if that were so, more log messages would have shown up.) > NOW PLUGGED IN TO WINDOWS 10 LAPTOP > (after a second, file browser opened showing root folder of memory storage) > [ 446.454380] dwc2 20980000.usb: new device is high-speed > [ 452.045884] dwc2 20980000.usb: new device is high-speed > [ 452.204357] dwc2 20980000.usb: new device is high-speed > [ 452.305171] dwc2 20980000.usb: new address 7 > [ 452.402701] g_mass_storage gadget: high-speed config #1: Linux File-Backed Storage High speed would also be correct. I assume that your System 2 doesn't support high speed, however. > DISCONNECTED AND RECONNECTED TO SYSTEM 2 > [ 522.097785] WARNING: CPU: 0 PID: 0 at drivers/usb/dwc2/gadget.c:176 dwc2_hsotg_init_fifo+0x188/0x1a8 [dwc2]() > [ 522.097802] Modules linked in: g_mass_storage bnep hci_uart btbcm bluetooth brcmfmac brcmutil snd_bcm2835 cfg80211 rfkill snd_pcm snd_timer snd dwc2 bcm2835_gpiomem bcm2835_wdt uio_pdrv_genirq uio usb_f_mass_storage libcomposite udc_core ipv6 > [ 522.097906] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.50+ #970 > [ 522.097918] Hardware name: BCM2708 > [ 522.097986] [<c0016d18>] (unwind_backtrace) from [<c0013c3c>] (show_stack+0x20/0x24) > [ 522.098025] [<c0013c3c>] (show_stack) from [<c02e49dc>] (dump_stack+0x20/0x28) > [ 522.098062] [<c02e49dc>] (dump_stack) from [<c0021f2c>] (warn_slowpath_common+0x8c/0xc4) > [ 522.098094] [<c0021f2c>] (warn_slowpath_common) from [<c0022020>] (warn_slowpath_null+0x2c/0x34) > [ 522.098207] [<c0022020>] (warn_slowpath_null) from [<bf0d3938>] (dwc2_hsotg_init_fifo+0x188/0x1a8 [dwc2]) > [ 522.098382] [<bf0d3938>] (dwc2_hsotg_init_fifo [dwc2]) from [<bf0d54cc>] (dwc2_hsotg_core_init_disconnected+0x60/0x308 [dwc2]) > [ 522.098538] [<bf0d54cc>] (dwc2_hsotg_core_init_disconnected [dwc2]) from [<bf0d5c74>] (dwc2_hsotg_irq+0x500/0x6dc [dwc2]) > [ 522.098645] [<bf0d5c74>] (dwc2_hsotg_irq [dwc2]) from [<c005acf4>] (handle_irq_event_percpu+0x94/0x1f0) > [ 522.098679] [<c005acf4>] (handle_irq_event_percpu) from [<c005ae88>] (handle_irq_event+0x38/0x4c) > [ 522.098712] [<c005ae88>] (handle_irq_event) from [<c005dc14>] (handle_level_irq+0x9c/0x134) > [ 522.098741] [<c005dc14>] (handle_level_irq) from [<c005a368>] (generic_handle_irq+0x30/0x44) > [ 522.098769] [<c005a368>] (generic_handle_irq) from [<c005a600>] (__handle_domain_irq+0x58/0xb8) > [ 522.098803] [<c005a600>] (__handle_domain_irq) from [<c0010748>] (handle_IRQ+0x2c/0x30) > [ 522.098832] [<c0010748>] (handle_IRQ) from [<c000940c>] (bcm2835_handle_irq+0x3c/0x58) > [ 522.098868] [<c000940c>] (bcm2835_handle_irq) from [<c05768e4>] (__irq_svc+0x44/0x5c) > [ 522.098883] Exception stack(0xc0821f18 to 0xc0821f60) > [ 522.098900] 1f00: 00000000 00000000 > [ 522.098922] 1f20: 00000000 c0822f74 c088d5f0 c0820000 c08220ac 00000000 c0887d04 c0887268 > [ 522.098944] 1f40: c0887268 c0821f74 c0821f68 c0821f68 c0010804 c0010808 60000013 ffffffff > [ 522.098975] [<c05768e4>] (__irq_svc) from [<c0010808>] (arch_cpu_idle+0x30/0x40) > [ 522.099016] [<c0010808>] (arch_cpu_idle) from [<c004d7ec>] (default_idle_call+0x34/0x48) > [ 522.099046] [<c004d7ec>] (default_idle_call) from [<c004d930>] (cpu_startup_entry+0x130/0x17c) > [ 522.099074] [<c004d930>] (cpu_startup_entry) from [<c05722e0>] (rest_init+0x6c/0x84) > [ 522.099112] [<c05722e0>] (rest_init) from [<c07c2ca0>] (start_kernel+0x358/0x3cc) > [ 522.099128] ---[ end trace ff12c3310899125d ]--- That certainly indicates something went wrong. > [ 522.117486] dwc2 20980000.usb: new device is low-speed > [ 522.177563] dwc2 20980000.usb: new device is low-speed > [ 522.199215] dwc2 20980000.usb: new address 1 > [ 522.723225] g_mass_storage gadget: low-speed config #1: Linux File-Backed Storage > IS SHOWING UP CORRECTLY ON SYSTEM 2 That fact that it works here indicates that it isn't really connecting at low speed. g_mass_storage doesn't work at all in low speed. It's possible that the problem has already been fixed. You are using version 4.4.50 of the kernel, and version 4.12 was just released last week. Alternatively, maybe John Youn has some suggestions. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
