| Message ID | 1609768179-10132-11-git-send-email-loic.poulain@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | mhi: pci_generic: Misc improvements | expand |
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@linaro.org> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> 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 >
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, \
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@linaro.org> --- drivers/bus/mhi/pci_generic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.7.4