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> --- 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
