Re: [PATCH] IRQ/Platform-MSI:Increase the maximum MSIs the MSI framework can support.

["majun (F)" <majun258@huawei.com>]

在 2015/12/21 18:43, Marc Zyngier 写道:
> On Mon, 21 Dec 2015 11:18:25 +0800
> MaJun <majun258@huawei.com> wrote:
> 
>> From: Ma Jun <majun258@huawei.com>
>>
>> The current MSI framework can only support 256 platform MSIs.
>>
>> But on Hisilicon platform, some network related devices has about 500
>> wired interrupts.
>>
>> To support these devices, we need a new maximum value more than 256.
>>
>> Signed-off-by: Ma Jun <majun258@huawei.com>
>> ---
>>  drivers/base/platform-msi.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
>> index a203896..9c00d3f 100644
>> --- a/drivers/base/platform-msi.c
>> +++ b/drivers/base/platform-msi.c
>> @@ -24,7 +24,7 @@
>>  #include <linux/msi.h>
>>  #include <linux/slab.h>
>>  
>> -#define DEV_ID_SHIFT	24
>> +#define DEV_ID_SHIFT	22
>>  #define MAX_DEV_MSIS	(1 << (32 - DEV_ID_SHIFT))
>>  
>>  /*
> 
> If we bother doing that, why not directly aligning it with MSI-X and
> allow up to 2048 interrupts per device? It is only an extra bit, and
> that still leaves 21 bits worth of device IDs, while still having
> hwirq as an unsigned long (32bit on 32bit architectures).
> 

Ok, I'll changed this value to 2048

Thanks
Ma Jun
> Thanks,
> 
> 	M.
>