[Skiboot] [PATCH v2] Fix hvc console issue by using OPAL event.

[ppaidipe]

On 2017-05-04 11:40, Alistair Popple wrote:
> Hi Pridhiviraj,
> 
> There were some subtlties here with different kernel versions that
> unfortunately I only vaguely recall. Which specific kernel versions
> and systems have you tested this on? Sam do you think this will cause
> issues on Firenze when there is data on the second serial console?
> 
> Regards,
> 
> Alistair


Hi Alistair
I am seeing this failure currently on Firenze systems with
RHEL 7.3 kernel 3.10.0-510.el7.ppc64le. So tested this on that
combination. And also tested on ubuntu 16.04/16.10 kernel's
likely 4.8/4.10 kernel versions.
on OpenPower systems the failure was fixed.
https://patchwork.ozlabs.org/patch/693518/


Thanks
Pridhiviraj


> 
> On Wed, 22 Feb 2017 11:32:42 AM ppaidipe at linux.vnet.ibm.com wrote:
>> From: Pridhiviraj Paidipeddi <ppaidipe at linux.vnet.ibm.com>
>> 
>> This reverts part of commit 583c8203dcb26b42cea81e4734ea926dae05dbb9.
>> 
>> Below is the WARNING in pre 4.2 linux kernels which is raised in 
>> firenze
>> systems due to interrupts mapping failure.
>> 
>> [    0.947741] irq: irq-62==>hwirq-0x3e mapping failed: -22
>> [    0.947793] ------------[ cut here ]------------
>> [    0.947838] WARNING: at kernel/irq/irqdomain.c:485
>> 
>> So this commit 583c8203dcb26b42cea81e4734ea926dae05dbb9 is causing
>> the above kernel WARNING(found by git-bisect).
>> 
>> As per suggestion by Alistair, Use OPAL event instead of interrupts
>> to avoid the warning. Tested on RHEL and Ubuntu OS's, not seen any
>> kernel warning's.
>> 
>> [    1.745145] hvc0: raw protocol on /ibm,opal/consoles/serial at 0 (boot 
>> console)
>> [    1.745223] hvc0: No interrupts property, using OPAL event
>> [    1.745556] hvc1: hvsi protocol on /ibm,opal/consoles/serial at 1
>> [    1.745622] hvc1: No interrupts property, using OPAL event
>> 
>> Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe at linux.vnet.ibm.com>
>> ---
>> Changes since v1:
>> 
>> 	Use OPAL event instead of interrupts to avoid the
>> 	kernel warning.
>> 
>>  hw/fsp/fsp-console.c | 6 ------
>>  1 file changed, 6 deletions(-)
>> 
>> diff --git a/hw/fsp/fsp-console.c b/hw/fsp/fsp-console.c
>> index 6683679..2785a82 100644
>> --- a/hw/fsp/fsp-console.c
>> +++ b/hw/fsp/fsp-console.c
>> @@ -929,10 +929,8 @@ void fsp_console_reset(void)
>> 
>>  void fsp_console_add_nodes(void)
>>  {
>> -	struct dt_node *opal_event;
>>  	unsigned int i;
>> 
>> -	opal_event = dt_find_by_name(opal_node, "event");
>> 
>>  	for (i = 0; i < MAX_SERIAL; i++) {
>>  		struct fsp_serial *fs = &fsp_serials[i];
>> @@ -951,10 +949,6 @@ void fsp_console_add_nodes(void)
>> 
>>  		fs->irq = opal_dynamic_event_alloc();
>>  		dt_add_property_cells(fs_node, "interrupts", ilog2(fs->irq));
>> -
>> -		if (opal_event)
>> -			dt_add_property_cells(fs_node, "interrupt-parent",
>> -					      opal_event->phandle);
>>  	}
>>  }
>> 
>>