On Thu, Aug 22, 2024 at 09:48:48PM +0800, Peng Fan (OSS) wrote: > The i.MX7ULP Cortex-A7 is under control of Cortex-M4. The i.MX7ULP Linux > poweroff and restart rely on rpmsg driver to send a message to Cortex-M4 > firmware. Then Cortex-A7 could poweroff or restart by Cortex-M4 to > configure the i.MX7ULP power controller properly. > > However the reboot and restart kernel common code use atomic notifier, > see kernel/reboot.c: do_kernel_power_off, do_kernel_restart. > Linux 'poweroff' cmd will trigger kernel 'do_kernel_power_off' > Linux 'reboot' cmd will trigger kernel 'do_kernel_restart'. > > Power off and restart are totally different operations and are not > complementary. So need to make sure the mailbox be changed to non-blocking > mode in SYS_OFF_MODE_POWER_OFF_PREPARE and SYS_OFF_MODE_RESTART_PREPARE > stage. Otherwise with blocking tx mailbox, there will be kernel dump, > because of blocking mailbox will use wait_for_completion_timeout. In the > poweroff or restart case, there is no need to wait, because after M4 got > the message, M4 will put A7 to reboot or poweroff. > > patch 1 is to support non-blocking tx mailbox channel > patch 2 is to switch to non-blocking tx for system poweroff or restart. > > Signed-off-by: Peng Fan <peng.fan@xxxxxxx> > --- > Changes in v3: > - patch 2: Introduce an flags entry for dcfg and set IMX_RPROC_NEED_SYSTEM_OFF > for i.MX7ULP, drop used "struct sys_off_data data" and add comment(per Frank). > Drop R-b of patch 2 because of this change. > - Patch 1: commit log rewritten and R-b dropped. > (Thanks to Daniel). > - Update patch 2 commit log and cover-letter to clarify reboot and > poweroff are different operations and not complementary > (Thanks to Daniel). > - Link to v2: https://lore.kernel.org/r/20240719-imx_rproc-v2-0-cd8549aa3f1f@xxxxxxx > > Changes in v2: > - Separated patch 5,6 from v1 > - Update commit patch 1 with adding "No functional changes" > - Link to v1: https://lore.kernel.org/r/20240712-imx_rproc-v1-0-7bcf6732d328@xxxxxxx > > --- > Peng Fan (2): > remoteproc: imx_rproc: Allow setting of the mailbox transmit mode > remoteproc: imx_rproc: Add support for poweroff and reboot > > drivers/remoteproc/imx_rproc.c | 54 +++++++++++++++++++++++++++++++++++++----- > drivers/remoteproc/imx_rproc.h | 4 ++++ > 2 files changed, 52 insertions(+), 6 deletions(-) I have applied this set. Thanks, Mathieu > --- > base-commit: 33a32de2d79c051f27ed57c4ac90cdb406f91928 > change-id: 20240712-imx_rproc-25f3ab753c58 > > Best regards, > -- > Peng Fan <peng.fan@xxxxxxx> >
