Aaro Koskinen 2f963bfbd8 MIPS: Loongson: Fix random early boot hang ... Some Loongson boards (e.g. Lemote FuLoong mini-PC) use ISA/southbridge device (CS5536 general purpose timer) for the timer interrupt. It starts running early and is already enabled during the PCI configuration, during which there is a small window in pci_read_base() when the register access is temporarily disabled. If the timer interrupts at this point, the system will hang. Fix this by adding a fixup that keeps the register access always enabled. The hang the patch fixes usually looks like this: [ 0.844000] pci 0000:00:0e.0: [1022:2090] type 00 class 0x060100 [ 0.848000] pci 0000:00:0e.0: reg 10: [io 0xb410-0xb417] [ 0.852000] pci 0000:00:0e.0: reg 14: [io 0xb000-0xb0ff] [ 0.856000] pci 0000:00:0e.0: reg 18: [io 0xb380-0xb3bf] [ 28.140000] BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1] [ 28.140000] Modules linked in: [ 28.140000] irq event stamp: 37965 [ 28.140000] hardirqs last enabled at (37964): [<ffffffff80204c0c>] restore_partial+0x6c/0x13c [ 28.140000] hardirqs last disabled at (37965): [<ffffffff80204f8c>] handle_int+0x144/0x15c [ 28.140000] softirqs last enabled at (24316): [<ffffffff802381f4>] __do_softirq+0x1cc/0x258 [ 28.140000] softirqs last disabled at (24327): [<ffffffff80238420>] do_softirq+0xc8/0xd0 [ 28.140000] Cpu 0 [ 28.140000] $ 0 : 0000000000000000 00000000140044e1 980000009f090000 0000000000000001 [ 28.140000] $ 4 : 980000009f090000 0000000000000000 0000000000000100 03b7fff87fbde011 [ 28.140000] $ 8 : ffffffff812b1928 000000000001e000 043ffff87fbde011 fffffff87fbde011 [ 28.140000] $12 : 000000000000000e ffffffff807a0000 0000000000000698 0000000000000000 [ 28.140000] $16 : 0000000000000002 ffffffff81055e20 ffffffff80786810 0000000000000000 [ 28.140000] $20 : 000000000000000a ffffffff807bc244 ffffffff807e6350 ffffffff80770000 [ 28.140000] $24 : 0000000000000d80 00000000fffedbe0 [ 28.140000] $28 : 980000009f07c000 980000009f07fa10 ffffffff81050000 ffffffff802380f8 [ 28.140000] Hi : 0000000000d0fc00 [ 28.140000] Lo : 0000000000f82b40 [ 28.140000] epc : ffffffff8023810c __do_softirq+0xe4/0x258 [ 28.140000] Not tainted [ 28.140000] ra : ffffffff802380f8 __do_softirq+0xd0/0x258 [ 28.140000] Status: 140044e3 KX SX UX KERNEL EXL IE [ 28.140000] Cause : 10008400 [ 28.140000] PrId : 00006303 (ICT Loongson-2) Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/4958/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>		2013-06-21 18:07:01 +02:00
..
common	MIPS: Loongson: Fix random early boot hang	2013-06-21 18:07:01 +02:00
fuloong-2e	MIPS: Whitespace cleanup.	2013-02-01 10:00:22 +01:00
lemote-2f	MIPS: Whitespace cleanup.	2013-02-01 10:00:22 +01:00
Kconfig	MIPS: Loongson 2: Sort out clock managment.	2012-08-01 18:10:06 +02:00
Makefile	MIPS: Whitespace cleanup.	2013-02-01 10:00:22 +01:00
Platform	MIPS: Loongson: Migrate makefile to new Platform file	2010-08-05 13:25:45 +01:00