On Mon, Jan 04, 2021 at 02:49:39PM +0100, Loic Poulain wrote:
> MHI hardware channels are usually the hardware accelerated data path
> e.g. IP packets path for modems. This path needs to be optimized for
> low latency and high throughput. After several tests on FN980m SDX55
> based modem, it seems 1ms is a good default irq_moderation value:
>
> - It allows to reach the maximum download throughput
> - It introduces limited latency (5ms is too high)
> - It prevents interrupt flooding
>
> Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Thanks,
Mani
> ---
> drivers/bus/mhi/pci_generic.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
> index a4b6221..1603c83 100644
> --- a/drivers/bus/mhi/pci_generic.c
> +++ b/drivers/bus/mhi/pci_generic.c
> @@ -130,7 +130,7 @@ struct mhi_pci_dev_info {
> #define MHI_EVENT_CONFIG_HW_DATA(ev_ring, ch_num) \
> { \
> .num_elements = 256, \
> - .irq_moderation_ms = 5, \
> + .irq_moderation_ms = 1, \
> .irq = (ev_ring) + 1, \
> .priority = 1, \
> .mode = MHI_DB_BRST_DISABLE, \
> --
> 2.7.4
>
