[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH] serial: Skip over PCIe device which have no quirks (fix AMT regression).



On 3/5/2014 3:09 PM, Konrad Rzeszutek Wilk wrote:
See:
00:16.0 Communication controller: Intel Corporation Cougar Point HECI 
Controller #1 (rev 04)
         Subsystem: Intel Corporation Device 2008
         Flags: bus master, fast devsel, latency 0, IRQ 11
         Memory at fb12a000 (64-bit, non-prefetchable) [size=16]
00:16.3 Serial controller: Intel Corporation Cougar Point KT Controller (rev 
04) (prog-if 02 [16550])
         Subsystem: Intel Corporation Device 2008
         Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 17
         I/O ports at f0e0 [size=8]
         Memory at fb129000 (32-bit, non-prefetchable) [size=4K]

pci 0000:00:16.0: [8086:1c3a] type 00 class 0x078000
pci 0000:00:16.3: [8086:1c3d] type 00 class 0x070002

And Xen picks 00:16.0 as its console when using 'com1=115200,8n1,amt'.

This patch fixes it and allows us to use AMT again by zeroing
out io_base to zero. If the scan did not work, the io_base is
set back to a default value.

If you provide 'amt' on command line => 'skip_amt' = 0
Then we'd just return -1 without setting io_base to 0x3f8 due to this condition-
if ( !skip_amt )
   return -1;

(or am I missing something?)


diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 487bf7d..9f87018 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -829,6 +829,7 @@ pci_uart_config (struct ns16550 *uart, int skip_amt, int 
bar_idx)
      unsigned int b, d, f, nextf, i;
      u16 vendor, device;
+ uart->io_base = 0;

Why not set ns16550.io_base = 0; in arch/x86/setup.c ?
AFAICT, ns16550.c is the only one that uses ns16550_defaults structure, so it should be safe..


Thanks,
-Aravind.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.