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. Regards, Bjorn
