2014-01-29 David Laight <David.Laight@xxxxxxxxxx>: >> Maybe I misunderstand something, but won't that commit end up replacing >> the previous pair of writel() with a single native writeq() on 64bit >> platforms? >> >> Judging by the comment in front of the xhci_write_64(), that might not >> necessarily be supported on all xHCI implementations: >> >> * Some xHCI implementations may support 64-bit address pointers. Registers >> * with 64-bit address pointers should be written to with dword accesses by >> * writing the low dword first (ptr[0]), then the high dword (ptr[1]) second. >> * xHCI implementations that do not support 64-bit address pointers will ignore >> * the high dword, and write order is irrelevant. >> >> I wonder if (some of) these implementations actually depend on this >> two-cycle write, making __raw_writeq() fail? > > I think this is a 32bit kernel on hardware that would support a 64bit one. This is notebook with i7-2670QM, see cpuinfo.txt for details. I use x86_64 kernel: CONFIG_64BIT=y CONFIG_X86_64=y CONFIG_X86=y (see attached config for details). > So the xhci controller supports 64 bits addressing (etc) but the cpu doesn't > have a 64bit write, so writeq() will do two 32bit accesses. > ISTR that these are in the correct order. > I assume the required compiler barrier is present. I've enabled some debugging in xhci-dbg.c, does it help? xhci_hcd 0000:04:00.0: xHCI capability registers at ffffc90004e60000: xhci_hcd 0000:04:00.0: CAPLENGTH AND HCIVERSION 0x960020: xhci_hcd 0000:04:00.0: CAPLENGTH: 0x20 xhci_hcd 0000:04:00.0: HCIVERSION: 0x96 xhci_hcd 0000:04:00.0: HCSPARAMS 1: 0x4000820 xhci_hcd 0000:04:00.0: Max device slots: 32 xhci_hcd 0000:04:00.0: Max interrupters: 8 xhci_hcd 0000:04:00.0: Max ports: 4 xhci_hcd 0000:04:00.0: HCSPARAMS 2: 0x17f1 xhci_hcd 0000:04:00.0: Isoc scheduling threshold: 1 xhci_hcd 0000:04:00.0: Maximum allowed segments in event ring: 15 xhci_hcd 0000:04:00.0: HCSPARAMS 3 0x0: xhci_hcd 0000:04:00.0: Worst case U1 device exit latency: 0 xhci_hcd 0000:04:00.0: Worst case U2 device exit latency: 0 xhci_hcd 0000:04:00.0: HCC PARAMS 0x200f180: xhci_hcd 0000:04:00.0: HC generates 32 bit addresses xhci_hcd 0000:04:00.0: FIXME: more HCCPARAMS debugging xhci_hcd 0000:04:00.0: RTSOFF 0x1000: -- Rafał
processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 2296.851 cache size : 6144 KB physical id : 0 siblings : 8 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 2802.851 cache size : 6144 KB physical id : 0 siblings : 8 core id : 1 cpu cores : 4 apicid : 2 initial apicid : 2 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 2 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 2725.851 cache size : 6144 KB physical id : 0 siblings : 8 core id : 2 cpu cores : 4 apicid : 4 initial apicid : 4 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 3 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 1078.085 cache size : 6144 KB physical id : 0 siblings : 8 core id : 3 cpu cores : 4 apicid : 6 initial apicid : 6 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 4 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 2955.820 cache size : 6144 KB physical id : 0 siblings : 8 core id : 0 cpu cores : 4 apicid : 1 initial apicid : 1 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 5 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 1595.859 cache size : 6144 KB physical id : 0 siblings : 8 core id : 1 cpu cores : 4 apicid : 3 initial apicid : 3 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 6 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 2685.632 cache size : 6144 KB physical id : 0 siblings : 8 core id : 2 cpu cores : 4 apicid : 5 initial apicid : 5 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz stepping : 7 microcode : 0x29 cpu MHz : 2371.187 cache size : 6144 KB physical id : 0 siblings : 8 core id : 3 cpu cores : 4 apicid : 7 initial apicid : 7 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid bogomips : 4390.07 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management:
Attachment:
config
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