On 08/31/18 13:55, Bjorn Andersson wrote: > On Fri 31 Aug 13:41 PDT 2018, Frank Rowand wrote: > >> On 08/30/18 21:07, Bjorn Andersson wrote: >>> On Thu 30 Aug 20:57 PDT 2018, Frank Rowand wrote: >>> >>>> Hi Bjorn, >>>> >>>> >>>> On 04/19/18 18:17, Bjorn Andersson wrote: >>>>> Attempt to acquire the APCS IPC through the mailbox framework and fall >>>>> back to the old syscon based approach, to allow us to move away from >>>>> using the syscon. >>>>> >>>>> Reviewed-by: Arun Kumar Neelakantam <aneela@xxxxxxxxxxxxxx> >>>>> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> >>>>> --- >>>>> >>>>> Changes since v2: >>>>> - Added comment about mbox_send_message() return value. >>>>> >>>>> .../devicetree/bindings/soc/qcom/qcom,smd.txt | 8 ++- >>>>> drivers/rpmsg/Kconfig | 1 + >>>>> drivers/rpmsg/qcom_smd.c | 67 ++++++++++++++++------ >>>>> 3 files changed, 56 insertions(+), 20 deletions(-) >>>> >>>> This patch in the mainline Linux kernel as commit ab460a2e72dabecfdabd45eb7e3ee2d73fc876d4 >>>> causes a problem with the APQ8074 Dragonboard. The mmc device is not set up >>>> with the patch applied, thus I do not have the block device my root file system >>>> is located on. >>>> >>>> Testing on v4.18, if I revert this commit the mmc device is available. >>>> >>>> I'll reply to this email with the console messages for 4.18 and for 4.18 with >>>> this commit reverted. >>>> >>> >>> The mmc device would fail to come up if the regulators didn't come up, >>> which would be the result of smd not working. But it should fallback to >>> the old mechanism if no mailbox is specified. >>> >>> Can you double check that CONFIG_RPMSG_QCOM_SMD is still set in your >>> .config after applying and building with this commit included? And if >>> not, try to enable CONFIG_MAILBOX. >> >> Thank you! >> >> That is indeed the cause. ab460a2e72da added a "depends on MAILBOX" to >> CONFIG_RPMSG_QCOM_SMD, so CONFIG_RPMSG_QCOM_SMD becomes unset since >> CONFIG_MAILBOX is not enabled in qcom_defconfig and is not otherwise >> selected for the dragonboard. >> > > Thanks for verifying this! > >> Is there a config variable that should be selecting MAILBOX for a class >> of systems that would include the APQ8074 Dragonboard? For my testing >> I added the "select MAILBOX" to CONFIG_ARCH_MSM8974, but I do not know >> what systems that includes, and whether it is appropriate to do the >> select for all of them. >> > > We typically don't use the CONFIG_ARCH_* to enable user selectable > config options, even if they serve a critical role in the system. > > So minimum change would be to add CONFIG_MAILBOX to the qcom_defconfig > (and multi_v7_defconfig I presume). The fuller solution would be to add > qcom,msm8974-apcs-kpss-global (.data is 8) to the qcom-apcs-ipc-mailbox > list of compatibles and replace the syscon currently used, and then > enable these in the defconfigs. I would be happy with either solution. Can I twist your arm to create the patch? > > Regards, > Bjorn >
