[PATCH] IRQ/Platform-MSI:Increase the maximum MSIs the MSI framework can support.
majun258 at huawei.com
Mon Dec 21 18:46:56 PST 2015
在 2015/12/21 18:43, Marc Zyngier 写道:
> On Mon, 21 Dec 2015 11:18:25 +0800
> MaJun <majun258 at huawei.com> wrote:
>> From: Ma Jun <majun258 at 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 at 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
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