1 BusLogic MultiMaster and FlashPoint SCSI Driver for Linux
3 Version 2.0.15 for Linux 2.0
4 Version 2.1.15 for Linux 2.1
14 Copyright 1995-1998 by Leonard N. Zubkoff <lnz@dandelion.com>
19 BusLogic, Inc. designed and manufactured a variety of high performance SCSI
20 host adapters which share a common programming interface across a diverse
21 collection of bus architectures by virtue of their MultiMaster ASIC technology.
22 BusLogic was acquired by Mylex Corporation in February 1996, but the products
23 supported by this driver originated under the BusLogic name and so that name is
24 retained in the source code and documentation.
26 This driver supports all present BusLogic MultiMaster Host Adapters, and should
27 support any future MultiMaster designs with little or no modification. More
28 recently, BusLogic introduced the FlashPoint Host Adapters, which are less
29 costly and rely on the host CPU, rather than including an onboard processor.
30 Despite not having an onboard CPU, the FlashPoint Host Adapters perform very
31 well and have very low command latency. BusLogic has recently provided me with
32 the FlashPoint Driver Developer's Kit, which comprises documentation and freely
33 redistributable source code for the FlashPoint SCCB Manager. The SCCB Manager
34 is the library of code that runs on the host CPU and performs functions
35 analogous to the firmware on the MultiMaster Host Adapters. Thanks to their
36 having provided the SCCB Manager, this driver now supports the FlashPoint Host
39 My primary goals in writing this completely new BusLogic driver for Linux are
40 to achieve the full performance that BusLogic SCSI Host Adapters and modern
41 SCSI peripherals are capable of, and to provide a highly robust driver that can
42 be depended upon for high performance mission critical applications. All of
43 the major performance features can be configured from the Linux kernel command
44 line or at module initialization time, allowing individual installations to
45 tune driver performance and error recovery to their particular needs.
47 The latest information on Linux support for BusLogic SCSI Host Adapters, as
48 well as the most recent release of this driver and the latest firmware for the
49 BT-948/958/958D, will always be available from my Linux Home Page at URL
50 "http://www.dandelion.com/Linux/".
52 Bug reports should be sent via electronic mail to "lnz@dandelion.com". Please
53 include with the bug report the complete configuration messages reported by the
54 driver and SCSI subsystem at startup, along with any subsequent system messages
55 relevant to SCSI operations, and a detailed description of your system's
56 hardware configuration.
58 Mylex has been an excellent company to work with and I highly recommend their
59 products to the Linux community. In November 1995, I was offered the
60 opportunity to become a beta test site for their latest MultiMaster product,
61 the BT-948 PCI Ultra SCSI Host Adapter, and then again for the BT-958 PCI Wide
62 Ultra SCSI Host Adapter in January 1996. This was mutually beneficial since
63 Mylex received a degree and kind of testing that their own testing group cannot
64 readily achieve, and the Linux community has available high performance host
65 adapters that have been well tested with Linux even before being brought to
66 market. This relationship has also given me the opportunity to interact
67 directly with their technical staff, to understand more about the internal
68 workings of their products, and in turn to educate them about the needs and
69 potential of the Linux community.
71 More recently, Mylex has reaffirmed the company's interest in supporting the
72 Linux community, and I am now working on a Linux driver for the DAC960 PCI RAID
73 Controllers. Mylex's interest and support is greatly appreciated.
75 Unlike some other vendors, if you contact Mylex Technical Support with a
76 problem and are running Linux, they will not tell you that your use of their
77 products is unsupported. Their latest product marketing literature even states
78 "Mylex SCSI host adapters are compatible with all major operating systems
79 including: ... Linux ...".
81 Mylex Corporation is located at 34551 Ardenwood Blvd., Fremont, California
82 94555, USA and can be reached at 510/796-6100 or on the World Wide Web at
83 http://www.mylex.com. Mylex HBA Technical Support can be reached by electronic
84 mail at techsup@mylex.com, by Voice at 510/608-2400, or by FAX at 510/745-7715.
85 Contact information for offices in Europe and Japan is available on the Web
91 o Configuration Reporting and Testing
93 During system initialization, the driver reports extensively on the host
94 adapter hardware configuration, including the synchronous transfer parameters
95 requested and negotiated with each target device. AutoSCSI settings for
96 Synchronous Negotiation, Wide Negotiation, and Disconnect/Reconnect are
97 reported for each target device, as well as the status of Tagged Queuing.
98 If the same setting is in effect for all target devices, then a single word
99 or phrase is used; otherwise, a letter is provided for each target device to
100 indicate the individual status. The following examples
101 should clarify this reporting format:
103 Synchronous Negotiation: Ultra
105 Synchronous negotiation is enabled for all target devices and the host
106 adapter will attempt to negotiate for 20.0 mega-transfers/second.
108 Synchronous Negotiation: Fast
110 Synchronous negotiation is enabled for all target devices and the host
111 adapter will attempt to negotiate for 10.0 mega-transfers/second.
113 Synchronous Negotiation: Slow
115 Synchronous negotiation is enabled for all target devices and the host
116 adapter will attempt to negotiate for 5.0 mega-transfers/second.
118 Synchronous Negotiation: Disabled
120 Synchronous negotiation is disabled and all target devices are limited to
121 asynchronous operation.
123 Synchronous Negotiation: UFSNUUU#UUUUUUUU
125 Synchronous negotiation to Ultra speed is enabled for target devices 0
126 and 4 through 15, to Fast speed for target device 1, to Slow speed for
127 target device 2, and is not permitted to target device 3. The host
128 adapter's SCSI ID is represented by the "#".
130 The status of Wide Negotiation, Disconnect/Reconnect, and Tagged Queuing
131 are reported as "Enabled", Disabled", or a sequence of "Y" and "N" letters.
133 o Performance Features
135 BusLogic SCSI Host Adapters directly implement SCSI-2 Tagged Queuing, and so
136 support has been included in the driver to utilize tagged queuing with any
137 target devices that report having the tagged queuing capability. Tagged
138 queuing allows for multiple outstanding commands to be issued to each target
139 device or logical unit, and can improve I/O performance substantially. In
140 addition, BusLogic's Strict Round Robin Mode is used to optimize host adapter
141 performance, and scatter/gather I/O can support as many segments as can be
142 effectively utilized by the Linux I/O subsystem. Control over the use of
143 tagged queuing for each target device as well as individual selection of the
144 tagged queue depth is available through driver options provided on the kernel
145 command line or at module initialization time. By default, the queue depth
146 is determined automatically based on the host adapter's total queue depth and
147 the number, type, speed, and capabilities of the target devices found. In
148 addition, tagged queuing is automatically disabled whenever the host adapter
149 firmware version is known not to implement it correctly, or whenever a tagged
150 queue depth of 1 is selected. Tagged queuing is also disabled for individual
151 target devices if disconnect/reconnect is disabled for that device.
153 o Robustness Features
155 The driver implements extensive error recovery procedures. When the higher
156 level parts of the SCSI subsystem request that a timed out command be reset,
157 a selection is made between a full host adapter hard reset and SCSI bus reset
158 versus sending a bus device reset message to the individual target device
159 based on the recommendation of the SCSI subsystem. Error recovery strategies
160 are selectable through driver options individually for each target device,
161 and also include sending a bus device reset to the specific target device
162 associated with the command being reset, as well as suppressing error
163 recovery entirely to avoid perturbing an improperly functioning device. If
164 the bus device reset error recovery strategy is selected and sending a bus
165 device reset does not restore correct operation, the next command that is
166 reset will force a full host adapter hard reset and SCSI bus reset. SCSI bus
167 resets caused by other devices and detected by the host adapter are also
168 handled by issuing a soft reset to the host adapter and re-initialization.
169 Finally, if tagged queuing is active and more than one command reset occurs
170 in a 10 minute interval, or if a command reset occurs within the first 10
171 minutes of operation, then tagged queuing will be disabled for that target
172 device. These error recovery options improve overall system robustness by
173 preventing individual errant devices from causing the system as a whole to
174 lock up or crash, and thereby allowing a clean shutdown and restart after the
175 offending component is removed.
177 o PCI Configuration Support
179 On PCI systems running kernels compiled with PCI BIOS support enabled, this
180 driver will interrogate the PCI configuration space and use the I/O port
181 addresses assigned by the system BIOS, rather than the ISA compatible I/O
182 port addresses. The ISA compatible I/O port address is then disabled by the
183 driver. On PCI systems it is also recommended that the AutoSCSI utility be
184 used to disable the ISA compatible I/O port entirely as it is not necessary.
185 The ISA compatible I/O port is disabled by default on the BT-948/958/958D.
187 o /proc File System Support
189 Copies of the host adapter configuration information together with updated
190 data transfer and error recovery statistics are available through the
191 /proc/scsi/BusLogic/<N> interface.
193 o Shared Interrupts Support
195 On systems that support shared interrupts, any number of BusLogic Host
196 Adapters may share the same interrupt request channel.
199 SUPPORTED HOST ADAPTERS
201 The following list comprises the supported BusLogic SCSI Host Adapters as of
202 the date of this document. It is recommended that anyone purchasing a BusLogic
203 Host Adapter not in the following table contact the author beforehand to verify
204 that it is or will be supported.
206 FlashPoint Series PCI Host Adapters:
208 FlashPoint LT (BT-930) Ultra SCSI-3
209 FlashPoint LT (BT-930R) Ultra SCSI-3 with RAIDPlus
210 FlashPoint LT (BT-920) Ultra SCSI-3 (BT-930 without BIOS)
211 FlashPoint DL (BT-932) Dual Channel Ultra SCSI-3
212 FlashPoint DL (BT-932R) Dual Channel Ultra SCSI-3 with RAIDPlus
213 FlashPoint LW (BT-950) Wide Ultra SCSI-3
214 FlashPoint LW (BT-950R) Wide Ultra SCSI-3 with RAIDPlus
215 FlashPoint DW (BT-952) Dual Channel Wide Ultra SCSI-3
216 FlashPoint DW (BT-952R) Dual Channel Wide Ultra SCSI-3 with RAIDPlus
218 MultiMaster "W" Series Host Adapters:
220 BT-948 PCI Ultra SCSI-3
221 BT-958 PCI Wide Ultra SCSI-3
222 BT-958D PCI Wide Differential Ultra SCSI-3
224 MultiMaster "C" Series Host Adapters:
226 BT-946C PCI Fast SCSI-2
227 BT-956C PCI Wide Fast SCSI-2
228 BT-956CD PCI Wide Differential Fast SCSI-2
229 BT-445C VLB Fast SCSI-2
230 BT-747C EISA Fast SCSI-2
231 BT-757C EISA Wide Fast SCSI-2
232 BT-757CD EISA Wide Differential Fast SCSI-2
233 BT-545C ISA Fast SCSI-2
234 BT-540CF ISA Fast SCSI-2
236 MultiMaster "S" Series Host Adapters:
238 BT-445S VLB Fast SCSI-2
239 BT-747S EISA Fast SCSI-2
240 BT-747D EISA Differential Fast SCSI-2
241 BT-757S EISA Wide Fast SCSI-2
242 BT-757D EISA Wide Differential Fast SCSI-2
243 BT-545S ISA Fast SCSI-2
244 BT-542D ISA Differential Fast SCSI-2
245 BT-742A EISA SCSI-2 (742A revision H)
246 BT-542B ISA SCSI-2 (542B revision H)
248 MultiMaster "A" Series Host Adapters:
250 BT-742A EISA SCSI-2 (742A revisions A - G)
251 BT-542B ISA SCSI-2 (542B revisions A - G)
253 AMI FastDisk Host Adapters that are true BusLogic MultiMaster clones are also
254 supported by this driver.
256 BusLogic SCSI Host Adapters are available packaged both as bare boards and as
257 retail kits. The BT- model numbers above refer to the bare board packaging.
258 The retail kit model numbers are found by replacing BT- with KT- in the above
259 list. The retail kit includes the bare board and manual as well as cabling and
260 driver media and documentation that are not provided with bare boards.
263 FLASHPOINT INSTALLATION NOTES
267 FlashPoint Host Adapters now include RAIDPlus, Mylex's bootable software
268 RAID. RAIDPlus is not supported on Linux, and there are no plans to support
269 it. The MD driver in Linux 2.0 provides for concatenation (LINEAR) and
270 striping (RAID-0), and support for mirroring (RAID-1), fixed parity (RAID-4),
271 and distributed parity (RAID-5) is available separately. The built-in Linux
272 RAID support is generally more flexible and is expected to perform better
273 than RAIDPlus, so there is little impetus to include RAIDPlus support in the
276 o Enabling UltraSCSI Transfers
278 FlashPoint Host Adapters ship with their configuration set to "Factory
279 Default" settings that are conservative and do not allow for UltraSCSI speed
280 to be negotiated. This results in fewer problems when these host adapters
281 are installed in systems with cabling or termination that is not sufficient
282 for UltraSCSI operation, or where existing SCSI devices do not properly
283 respond to synchronous transfer negotiation for UltraSCSI speed. AutoSCSI
284 may be used to load "Optimum Performance" settings which allow UltraSCSI
285 speed to be negotiated with all devices, or UltraSCSI speed can be enabled on
286 an individual basis. It is recommended that SCAM be manually disabled after
287 the "Optimum Performance" settings are loaded.
290 BT-948/958/958D INSTALLATION NOTES
292 The BT-948/958/958D PCI Ultra SCSI Host Adapters have some features which may
293 require attention in some circumstances when installing Linux.
295 o PCI I/O Port Assignments
297 When configured to factory default settings, the BT-948/958/958D will only
298 recognize the PCI I/O port assignments made by the motherboard's PCI BIOS.
299 The BT-948/958/958D will not respond to any of the ISA compatible I/O ports
300 that previous BusLogic SCSI Host Adapters respond to. This driver supports
301 the PCI I/O port assignments, so this is the preferred configuration.
302 However, if the obsolete BusLogic driver must be used for any reason, such as
303 a Linux distribution that does not yet use this driver in its boot kernel,
304 BusLogic has provided an AutoSCSI configuration option to enable a legacy ISA
307 To enable this backward compatibility option, invoke the AutoSCSI utility via
308 Ctrl-B at system startup and select "Adapter Configuration", "View/Modify
309 Configuration", and then change the "ISA Compatible Port" setting from
310 "Disable" to "Primary" or "Alternate". Once this driver has been installed,
311 the "ISA Compatible Port" option should be set back to "Disable" to avoid
312 possible future I/O port conflicts. The older BT-946C/956C/956CD also have
313 this configuration option, but the factory default setting is "Primary".
315 o PCI Slot Scanning Order
317 In systems with multiple BusLogic PCI Host Adapters, the order in which the
318 PCI slots are scanned may appear reversed with the BT-948/958/958D as
319 compared to the BT-946C/956C/956CD. For booting from a SCSI disk to work
320 correctly, it is necessary that the host adapter's BIOS and the kernel agree
321 on which disk is the boot device, which requires that they recognize the PCI
322 host adapters in the same order. The motherboard's PCI BIOS provides a
323 standard way of enumerating the PCI host adapters, which is used by the Linux
324 kernel. Some PCI BIOS implementations enumerate the PCI slots in order of
325 increasing bus number and device number, while others do so in the opposite
328 Unfortunately, Microsoft decided that Windows 95 would always enumerate the
329 PCI slots in order of increasing bus number and device number regardless of
330 the PCI BIOS enumeration, and requires that their scheme be supported by the
331 host adapter's BIOS to receive Windows 95 certification. Therefore, the
332 factory default settings of the BT-948/958/958D enumerate the host adapters
333 by increasing bus number and device number. To disable this feature, invoke
334 the AutoSCSI utility via Ctrl-B at system startup and select "Adapter
335 Configuration", "View/Modify Configuration", press Ctrl-F10, and then change
336 the "Use Bus And Device # For PCI Scanning Seq." option to OFF.
338 This driver will interrogate the setting of the PCI Scanning Sequence option
339 so as to recognize the host adapters in the same order as they are enumerated
340 by the host adapter's BIOS.
342 o Enabling UltraSCSI Transfers
344 The BT-948/958/958D ship with their configuration set to "Factory Default"
345 settings that are conservative and do not allow for UltraSCSI speed to be
346 negotiated. This results in fewer problems when these host adapters are
347 installed in systems with cabling or termination that is not sufficient for
348 UltraSCSI operation, or where existing SCSI devices do not properly respond
349 to synchronous transfer negotiation for UltraSCSI speed. AutoSCSI may be
350 used to load "Optimum Performance" settings which allow UltraSCSI speed to be
351 negotiated with all devices, or UltraSCSI speed can be enabled on an
352 individual basis. It is recommended that SCAM be manually disabled after the
353 "Optimum Performance" settings are loaded.
358 BusLogic Driver Options may be specified either via the Linux Kernel Command
359 Line or via the Loadable Kernel Module Installation Facility. Driver Options
360 for multiple host adapters may be specified either by separating the option
361 strings by a semicolon, or by specifying multiple "BusLogic=" strings on the
362 command line. Individual option specifications for a single host adapter are
363 separated by commas. The Probing and Debugging Options apply to all host
364 adapters whereas the remaining options apply individually only to the
365 selected host adapter.
367 The BusLogic Driver Probing Options comprise the following:
371 The "IO:" option specifies an ISA I/O Address to be probed for a non-PCI
372 MultiMaster Host Adapter. If neither "IO:" nor "NoProbeISA" options are
373 specified, then the standard list of BusLogic MultiMaster ISA I/O Addresses
374 will be probed (0x330, 0x334, 0x230, 0x234, 0x130, and 0x134). Multiple
375 "IO:" options may be specified to precisely determine the I/O Addresses to
376 be probed, but the probe order will always follow the standard list.
380 The "NoProbe" option disables all probing and therefore no BusLogic Host
381 Adapters will be detected.
385 The "NoProbeISA" option disables probing of the standard BusLogic ISA I/O
386 Addresses and therefore only PCI MultiMaster and FlashPoint Host Adapters
391 The "NoProbePCI" options disables the interrogation of PCI Configuration
392 Space and therefore only ISA Multimaster Host Adapters will be detected, as
393 well as PCI Multimaster Host Adapters that have their ISA Compatible I/O
394 Port set to "Primary" or "Alternate".
398 The "NoSortPCI" option forces PCI MultiMaster Host Adapters to be
399 enumerated in the order provided by the PCI BIOS, ignoring any setting of
400 the AutoSCSI "Use Bus And Device # For PCI Scanning Seq." option.
404 The "MultiMasterFirst" option forces MultiMaster Host Adapters to be probed
405 before FlashPoint Host Adapters. By default, if both FlashPoint and PCI
406 MultiMaster Host Adapters are present, this driver will probe for
407 FlashPoint Host Adapters first unless the BIOS primary disk is controlled
408 by the first PCI MultiMaster Host Adapter, in which case MultiMaster Host
409 Adapters will be probed first.
413 The "FlashPointFirst" option forces FlashPoint Host Adapters to be probed
414 before MultiMaster Host Adapters.
416 The BusLogic Driver Tagged Queuing Options allow for explicitly specifying
417 the Queue Depth and whether Tagged Queuing is permitted for each Target
418 Device (assuming that the Target Device supports Tagged Queuing). The Queue
419 Depth is the number of SCSI Commands that are allowed to be concurrently
420 presented for execution (either to the Host Adapter or Target Device). Note
421 that explicitly enabling Tagged Queuing may lead to problems; the option to
422 enable or disable Tagged Queuing is provided primarily to allow disabling
423 Tagged Queuing on Target Devices that do not implement it correctly. The
424 following options are available:
428 The "QueueDepth:" or QD:" option specifies the Queue Depth to use for all
429 Target Devices that support Tagged Queuing, as well as the maximum Queue
430 Depth for devices that do not support Tagged Queuing. If no Queue Depth
431 option is provided, the Queue Depth will be determined automatically based
432 on the Host Adapter's Total Queue Depth and the number, type, speed, and
433 capabilities of the detected Target Devices. For Host Adapters that
434 require ISA Bounce Buffers, the Queue Depth is automatically set by default
435 to BusLogic_TaggedQueueDepthBB or BusLogic_UntaggedQueueDepthBB to avoid
436 excessive preallocation of DMA Bounce Buffer memory. Target Devices that
437 do not support Tagged Queuing always have their Queue Depth set to
438 BusLogic_UntaggedQueueDepth or BusLogic_UntaggedQueueDepthBB, unless a
439 lower Queue Depth option is provided. A Queue Depth of 1 automatically
440 disables Tagged Queuing.
442 QueueDepth:[<integer>,<integer>...]
444 The "QueueDepth:[...]" or "QD:[...]" option specifies the Queue Depth
445 individually for each Target Device. If an <integer> is omitted, the
446 associated Target Device will have its Queue Depth selected automatically.
448 TaggedQueuing:Default
450 The "TaggedQueuing:Default" or "TQ:Default" option permits Tagged Queuing
451 based on the firmware version of the BusLogic Host Adapter and based on
452 whether the Queue Depth allows queuing multiple commands.
456 The "TaggedQueuing:Enable" or "TQ:Enable" option enables Tagged Queuing for
457 all Target Devices on this Host Adapter, overriding any limitation that
458 would otherwise be imposed based on the Host Adapter firmware version.
460 TaggedQueuing:Disable
462 The "TaggedQueuing:Disable" or "TQ:Disable" option disables Tagged Queuing
463 for all Target Devices on this Host Adapter.
465 TaggedQueuing:<Target-Spec>
467 The "TaggedQueuing:<Target-Spec>" or "TQ:<Target-Spec>" option controls
468 Tagged Queuing individually for each Target Device. <Target-Spec> is a
469 sequence of "Y", "N", and "X" characters. "Y" enables Tagged Queuing, "N"
470 disables Tagged Queuing, and "X" accepts the default based on the firmware
471 version. The first character refers to Target Device 0, the second to
472 Target Device 1, and so on; if the sequence of "Y", "N", and "X" characters
473 does not cover all the Target Devices, unspecified characters are assumed
476 The BusLogic Driver Miscellaneous Options comprise the following:
478 BusSettleTime:<seconds>
480 The "BusSettleTime:" or "BST:" option specifies the Bus Settle Time in
481 seconds. The Bus Settle Time is the amount of time to wait between a Host
482 Adapter Hard Reset which initiates a SCSI Bus Reset and issuing any SCSI
483 Commands. If unspecified, it defaults to BusLogic_DefaultBusSettleTime.
487 The "InhibitTargetInquiry" option inhibits the execution of an Inquire
488 Target Devices or Inquire Installed Devices command on MultiMaster Host
489 Adapters. This may be necessary with some older Target Devices that do not
490 respond correctly when Logical Units above 0 are addressed.
492 The BusLogic Driver Debugging Options comprise the following:
496 The "TraceProbe" option enables tracing of Host Adapter Probing.
500 The "TraceHardwareReset" option enables tracing of Host Adapter Hardware
505 The "TraceConfiguration" option enables tracing of Host Adapter
510 The "TraceErrors" option enables tracing of SCSI Commands that return an
511 error from the Target Device. The CDB and Sense Data will be printed for
512 each SCSI Command that fails.
516 The "Debug" option enables all debugging options.
518 The following examples demonstrate setting the Queue Depth for Target Devices
519 1 and 2 on the first host adapter to 7 and 15, the Queue Depth for all Target
520 Devices on the second host adapter to 31, and the Bus Settle Time on the
521 second host adapter to 30 seconds.
523 Linux Kernel Command Line:
525 linux BusLogic=QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30
527 LILO Linux Boot Loader (in /etc/lilo.conf):
529 append = "BusLogic=QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30"
531 INSMOD Loadable Kernel Module Installation Facility:
534 'BusLogic="QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30"'
536 NOTE: Module Utilities 2.1.71 or later is required for correct parsing
537 of driver options containing commas.
542 This distribution was prepared for Linux kernel version 2.0.35, but should be
543 compatible with 2.0.4 or any later 2.0 series kernel.
545 To install the new BusLogic SCSI driver, you may use the following commands,
546 replacing "/usr/src" with wherever you keep your Linux kernel source tree:
549 tar -xvzf BusLogic-2.0.15.tar.gz
550 mv README.* LICENSE.* BusLogic.[ch] FlashPoint.c linux/drivers/scsi
551 patch -p0 < BusLogic.patch (only for 2.0.33 and below)
556 Then install "arch/i386/boot/zImage" as your standard kernel, run lilo if
557 appropriate, and reboot.
560 BUSLOGIC ANNOUNCEMENTS MAILING LIST
562 The BusLogic Announcements Mailing List provides a forum for informing Linux
563 users of new driver releases and other announcements regarding Linux support
564 for BusLogic SCSI Host Adapters. To join the mailing list, send a message to
565 "buslogic-announce-request@dandelion.com" with the line "subscribe" in the
projects / linux-2.6 / blob