On Fri, Feb 05, 2021 at 09:36:35AM +0100, Loic Poulain wrote: > We met some sporadic modem crashes during high throughput testing, this > has been root caused to a lack of elements in the event ring. Indeed, > the modem is simply crashing when event ring becomes empty. > > It appears that the total number event ring elements is too low given > the performances of the modem (IPA hardware accelerator). This change > increases the number of elements in the hardware event ring to 2048, > which is aligned with what is defined in downstream version: > https://source.codeaurora.org/quic/la/kernel/msm-4.14/tree/arch/arm64/boot/dts/qcom/sm8150-mhi.dtsi?h=msm-4.14#n482 > > With this change, modem coes not crash anymore. > > Note: An event ring element is 16-Byte, so the total memory usage of > a hardware event ring is now 32KB. > > 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 5b3a23a4..c20f59e 100644 > --- a/drivers/bus/mhi/pci_generic.c > +++ b/drivers/bus/mhi/pci_generic.c > @@ -129,7 +129,7 @@ struct mhi_pci_dev_info { > > #define MHI_EVENT_CONFIG_HW_DATA(ev_ring, ch_num) \ > { \ > - .num_elements = 256, \ > + .num_elements = 2048, \ > .irq_moderation_ms = 1, \ > .irq = (ev_ring) + 1, \ > .priority = 1, \ > -- > 2.7.4 >
