2009/7/14 Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>: > On Tue, Jul 14, 2009 at 11:05:58AM +0200, javier Martin wrote: >> 2009/7/14 Daniel Mack <daniel@xxxxxxxx>: >> > On Tue, Jul 14, 2009 at 09:38:53AM +0200, javier Martin wrote: >> >> Well, I am using gdb for debugging the kernel through JTAG, >> >> it currently crashes in function "static int __init ehci_hcd_init(void)" >> >> when executing line "retval = platform_driver_register(&PLATFORM_DRIVER);". >> > >> > The platform_driver's probe function is also called. Set a breakpoint at >> > ehci_mxc_drv_probe(), the real crash must be there or in one the >> > functions called. >> > >> > Daniel >> > >> > >> Yeah, you are right, the hierarchy is as follows: >> >> ehci_mxc_setup() -> ehci_reset() -> ehci_hub_control() >> >> In "ehci_hub_control" it crashes in the following "ehci_readl": >> >> case USB_PORT_FEAT_POWER: >> if (HCS_PPC (ehci->hcs_params)) >> ehci_writel(ehci, >> temp & ~(PORT_RWC_BITS | PORT_POWER), >> status_reg); >> break; >> >> Where "status_reg" is 0xc4846184, it seems this is a wrong value >> because base address of USB in i.mx27 is 0x10024000. >> What do you think? > > 0xc4846184 is the kernel virtual address, not the physical address. The > value seems sane. > > Sascha > > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > You are right, silly me, I didn't notice the "ioremap". That is not the problem at all. However, I have disassembled the code which belongs to the crashing function which is the following: >> ehci_writel(ehci, >> temp & ~(PORT_RWC_BITS | PORT_POWER), >> status_reg); Dump of assembler code from 0xc0125a5c to 0xc0125b5c: 0xc0125a5c <ehci_hub_control+440>: bicne r3, r1, #4096 ; 0x1000 0xc0125a60 <ehci_hub_control+444>: bicne r3, r3, #42 ; 0x2a 0xc0125a64 <ehci_hub_control+448>: strne r3, [r4] First two instructions are executed properly. It is the "strne" instruction which fails. Final register values are: r3 = 0x80000000 r4 = 0xc4846184 So it is trying to store the value 0x80000000 in the address 0xc4846184 which is the PORTSC1 register (physical address 0x10024168). When executing this instruction the system crashes as previously explained. So, I have enabled a breakpoint in this assembler instruction so that I can let the system in the same state. Then I try the following openOCD commands: * Read, write, read TXFILLTUNING register using physical addresses. (gdb) mon arm926ejs mdw_phys 0x10024164 0x10024164: 00020000 (gdb) mon arm926ejs mww_phys 0x10024164 0x00040000 (gdb) mon arm926ejs mdw_phys 0x10024164 0x10024164: 00040000 * Read, write, read TXFILLTUNING register using virtual addresses. (gdb) mon mdw 0xc4846164 1 0xc4846164: 00020000 (gdb) mon mww 0xc4846164 0x00040000 (gdb) mon mdw 0xc4846164 1 0xc4846164: 00040000 * Read, write, read PORTSC1 register using physical addresses. (gdb) mon arm926ejs mdw_phys 0x10024184 0x10024184: 80000000 (gdb) mon arm926ejs mww_phys 0x10024184 0x80000000 memory write caused data abort (address: 0x10024184, size: 0x4, count: 0x1) error: access caused data abort, system possibly corrupted (gdb) mon arm926ejs mdw_phys 0x10024184 memory read caused data abort (address: 0x10024184, size: 0x4, count: 0x1) error: access caused data abort, system possibly corrupted 0x10024184: c4846140 * Read, write, read PORTSC1 register using virtual addresses. (gdb) mon mdw 0xc4846184 1 0xc4846184: 80000000 (gdb) mon mww 0xc4846184 0x80000000 memory write caused data abort (address: 0xc4846184, size: 0x4, count: 0x1) Runtime error, file "command.c", line 469: (gdb) mon mdw 0xc4846184 1 memory read caused data abort (address: 0xc4846184, size: 0x4, count: 0x1) Runtime error, file "command.c", line 469: I don't know why the write access to PORTSC1 register fails, while the one to TXFILLTUNING success. They are both registers from the USB. This would also discard a problem with the "ahb_clk". Any suggestion please? -- Javier Martin Vista Silicon S.L. Universidad de Cantabria CDTUC - FASE C - Oficina S-345 Avda de los Castros s/n 39005- Santander. Cantabria. Spain +34 942 25 32 60 www.vista-silicon.com -- Javier Martin Vista Silicon S.L. Universidad de Cantabria CDTUC - FASE C - Oficina S-345 Avda de los Castros s/n 39005- Santander. Cantabria. Spain +34 942 25 32 60 www.vista-silicon.com -- 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
