Excluding first megabyte of memory

Pavel Roskin proski at gnu.org
Fri Jun 20 16:01:29 BST 2003


Hello!

I tested my plx9052 driver on another machine (Pentium III with Intel
chipset) and found that it hangs without any messages, so that even Break
(analog of Alt-SysRq) on the serial console won't reboot it.  This
behavior is common for recent 2.4 and 2.5 kernels.

Fortunately, I found a workaround.  Everything is working fine if I
comment out this line in /etc/pcmcia/config:

include memory 0xc0000-0xfffff

The driver gets requests to allocate memory at 0xc8000, 0xdc000 and
0xe0000.  It hangs soon after the memory window is allocated at 0xe0000.

It's interesting that the TI bridge using yenta module cannot use that
region either, but it doesn't hang:

cs: memory probe 0x0c0000-0x0fffff: excluding 0xc0000-0xfffff
cs: memory probe 0x60000000-0x60ffffff: clean.

I'd like to hear suggestions how to handle this situation.  If plx9052
driver ever goes to the kernel, I don't want to require every user to read
README and edit /etc/pcmcia/config.

Possible suggestions:

1) Change pcmcia-cs default config to try addresses above 1M first.
2) Disable map below 1M in the driver.
3) Same but only in i386 architecture.
4) Same but only for "bad" chipsets.

-- 
Regards,
Pavel Roskin-------------- next part --------------
00:00.0 Host bridge: Intel Corp. 82810E DC-133 GMCH [Graphics Memory Controller Hub] (rev 03)
00:01.0 VGA compatible controller: Intel Corp. 82810E DC-133 CGC [Chipset Graphics Controller] (rev 03)
00:1e.0 PCI bridge: Intel Corp. 82801AA PCI Bridge (rev 02)
00:1f.0 ISA bridge: Intel Corp. 82801AA ISA Bridge (LPC) (rev 02)
00:1f.1 IDE interface: Intel Corp. 82801AA IDE (rev 02)
00:1f.2 USB Controller: Intel Corp. 82801AA USB (rev 02)
00:1f.3 SMBus: Intel Corp. 82801AA SMBus (rev 02)
00:1f.5 Multimedia audio controller: Intel Corp. 82801AA AC'97 Audio (rev 02)
01:00.0 Network controller: Standard Microsystems Corp [SMC] SMC2602W EZConnect / Addtron AWA-100 (rev 02)
01:01.0 CardBus bridge: Texas Instruments PCI1410 PC card Cardbus Controller (rev 01)
01:07.0 Ethernet controller: Intel Corp. 82557/8/9 [Ethernet Pro 100] (rev 08)
-------------- next part --------------
00000000-0009ffff : System RAM
000a0000-000bffff : Video RAM area
000c0000-000c7fff : Video ROM
000cc000-000d97ff : Extension ROM
000f0000-000fffff : System ROM
00100000-0feeffff : System RAM
  00100000-00209e36 : Kernel code
  00209e37-002704ff : Kernel data
10000000-103fffff : PCI CardBus #02
60000000-60000fff : card services
d0000000-d3ffffff : Intel Corp. 82810E DC-133 CGC [Chipset Graphics Controller]
d5000000-d50fffff : Intel Corp. 82557/8/9 [Ethernet Pro 100]
  d5000000-d50fffff : e100
d5100000-d5101fff : PCI CardBus #02
d5103000-d5103fff : Intel Corp. 82557/8/9 [Ethernet Pro 100]
  d5103000-d5103fff : e100
d5104000-d5104fff : Standard Microsystems Corp [SMC] SMC2602W EZConnect / Addtron AWA-100
d5105000-d5105fff : Texas Instruments PCI1410 PC card Cardbus Controller
d6000000-d607ffff : Intel Corp. 82810E DC-133 CGC [Chipset Graphics Controller]


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