Re: [PATCH v2] bus: mhi: core: Add support MHI EE FP for download firmware

From: Bhaumik Bhatt
Date: Tue Nov 03 2020 - 12:33:02 EST


On 2020-11-02 17:47, Carl Yin wrote:
Hi bbhatt:

On November 03, 2020 12:34 AM, Bhatt wrote:
On 2020-11-02 04:27, carl.yin@xxxxxxxxxxx wrote:
> From: "carl.yin" <carl.yin@xxxxxxxxxxx>
>
> MHI wwan modems support download firmware to nand or emmc by firehose
> protocol, process as next:
> 1. modem boot up and enter EE AMSS, create DIAG channels (4, 5) device
> 2. user space tool send EDL command via DIAG channel,
> then modem enter EE EDL
> 3. boot.c download 'flash programmer image' via BHI interface 4. modem
> enter EE FP, and create EDL channels (34, 35) device 5. user space
> tool download 'firmware image' to modem via EDL channels
> by firehose protocol
>
> Signed-off-by: carl.yin <carl.yin@xxxxxxxxxxx>
> ---
> drivers/bus/mhi/core/init.c | 2 ++
> drivers/bus/mhi/core/internal.h | 1 +
> drivers/bus/mhi/core/main.c | 5 ++++-
> drivers/bus/mhi/core/pm.c | 13 ++++++++++++-
> include/linux/mhi.h | 4 +++-
> 5 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index ac4aa5c..e34616b 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -26,6 +26,7 @@ const char * const mhi_ee_str[MHI_EE_MAX] = {
> [MHI_EE_WFW] = "WFW",
> [MHI_EE_PTHRU] = "PASS THRU",
> [MHI_EE_EDL] = "EDL",
> + [MHI_EE_FP] = "FLASH PROGRAMMER",
> [MHI_EE_DISABLE_TRANSITION] = "DISABLE",
> [MHI_EE_NOT_SUPPORTED] = "NOT SUPPORTED", }; @@ -35,6 +36,7 @@
> const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
> [DEV_ST_TRANSITION_READY] = "READY",
> [DEV_ST_TRANSITION_SBL] = "SBL",
> [DEV_ST_TRANSITION_MISSION_MODE] = "MISSION_MODE",
> + [DEV_ST_TRANSITION_FP] = "FLASH_PROGRAMMER",
> [DEV_ST_TRANSITION_SYS_ERR] = "SYS_ERR",
> [DEV_ST_TRANSITION_DISABLE] = "DISABLE", }; diff --git
> a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
> index 4abf0cf..6ae897a 100644
> --- a/drivers/bus/mhi/core/internal.h
> +++ b/drivers/bus/mhi/core/internal.h
> @@ -386,6 +386,7 @@ enum dev_st_transition {
> DEV_ST_TRANSITION_READY,
> DEV_ST_TRANSITION_SBL,
> DEV_ST_TRANSITION_MISSION_MODE,
> + DEV_ST_TRANSITION_FP,
> DEV_ST_TRANSITION_SYS_ERR,
> DEV_ST_TRANSITION_DISABLE,
> DEV_ST_TRANSITION_MAX,
> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
> index 3950792..a1e1561 100644
> --- a/drivers/bus/mhi/core/main.c
> +++ b/drivers/bus/mhi/core/main.c
> @@ -422,7 +422,7 @@ irqreturn_t mhi_intvec_threaded_handler(int
> irq_number, void *priv)
> wake_up_all(&mhi_cntrl->state_event);
>
> /* For fatal errors, we let controller decide next step */
> - if (MHI_IN_PBL(ee))
> + if (MHI_IN_PBL(mhi_cntrl->ee))
Let's please have this as a separate patch with a fixes tag, as it fixes a pre-existing
bug. I am sure Mani would want this.
> mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_FATAL_ERROR);
> else
> mhi_pm_sys_err_handler(mhi_cntrl);
> @@ -782,6 +782,9 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller
> *mhi_cntrl,
> case MHI_EE_SBL:
> st = DEV_ST_TRANSITION_SBL;
> break;
> + case MHI_EE_FP:
> + st = DEV_ST_TRANSITION_FP;
> + break;
When do you get this EE event on the control event ring? Does it come by after
you have detected EE as FP from mhi_sync_power_up() and move to ready and
then M0?
[carl.yin] it is from the log, next is the sdx24's log.
Another thing, I find mhi controller's status_cb() should not directly
call mhi_power_down(),
The function stack is
mhi_intvec_threaded_handler()->status_cb()->mhi_power_down()->free_irq().
Should not free irq in the irq thread.

[ 304.263111] mhi 0000:03:00.0: Preparing channel: 4
[ 304.275580] mhi 0000:03:00.0: Chan: 4 successfully moved to start state
[ 304.275580] mhi 0000:03:00.0: Preparing channel: 5
[ 304.285901] mhi 0000:03:00.0: Chan: 5 successfully moved to start state
[ 307.380999] mhi 0000:03:00.0: local ee:EDL device ee:AMSS dev_state:SYS_ERR
[ 307.381000] mhi 0000:03:00.0: System error detected
[ 307.381001] mhi-pci-generic 0000:03:00.0: mhi_pci_status_cb ee=6, cb=7
[ 307.381006] mhi 0000:03:00.0: Handling state transition: DISABLE
[ 307.381007] mhi 0000:03:00.0: Transitioning from PM state: SYS_ERR
Detect to: SHUTDOWN Process
[ 307.381008] mhi 0000:03:00.0: Triggering MHI Reset in device
[ 307.381114] mhi 0000:03:00.0: local ee:EDL device ee:DISABLE dev_state:RESET
[ 307.381120] mhi 0000:03:00.0: Waiting for all pending event ring
processing to complete
[ 307.381120] mhi 0000:03:00.0: Waiting for all pending threads to complete
[ 307.381121] mhi 0000:03:00.0: Reset all active channels and remove
MHI devices
......
[ 307.402279] mhi 0000:03:00.0: Resetting EV CTXT and CMD CTXT
[ 307.402280] mhi 0000:03:00.0: Exiting with PM state: DISABLE, MHI
state: RESET
[ 307.402567] mhi 0000:03:00.0: Requested to power ON
[ 307.402845] mhi 0000:03:00.0: Power on setup success
[ 307.402847] mhi 0000:03:00.0: Handling state transition: PBL
[ 307.402985] mhi 0000:03:00.0: Starting SBL download via BHI.
Session ID:1048927456
[ 307.435259] mhi 0000:03:00.0: local ee:EDL device ee:EDL dev_state:RESET
[ 308.460322] mhi 0000:03:00.0: local ee:FLASH PROGRAMMER device
ee:EDL dev_state:READY
[ 308.460326] mhi 0000:03:00.0: Handling state transition: READY
[ 308.460335] mhi 0000:03:00.0: Device in READY State
[ 308.460335] mhi 0000:03:00.0: Initializing MHI registers
[ 308.464301] mhi 0000:03:00.0: State change event to state: M0
[ 308.465303] mhi 0000:03:00.0: Received EE event: FLASH PROGRAMMER
[ 308.465311] mhi 0000:03:00.0: Handling state transition: FLASH_PROGRAMMER
[ 309.381506] mhi 0000:03:00.0: Preparing channel: 34
[ 309.384631] mhi 0000:03:00.0: Chan: 34 successfully moved to start state
[ 309.384631] mhi 0000:03:00.0: Preparing channel: 35
[ 309.387910] mhi 0000:03:00.0: Chan: 35 successfully moved to start state

Yes, you should not call mhi_power_down() from the status_cb() directly. It is a
blocking function which should not called from a threaded IRQ handler, if
possible and it also ends up freeing the IRQ from the handler itself which should
not be done. Can you spawn a separate thread to do this work?
> case MHI_EE_WFW:
> case MHI_EE_AMSS:
> st = DEV_ST_TRANSITION_MISSION_MODE; diff --git
> a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index
> 3de7b16..2d68812 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -658,6 +658,12 @@ void mhi_pm_st_worker(struct work_struct *work)
> case DEV_ST_TRANSITION_MISSION_MODE:
> mhi_pm_mission_mode_transition(mhi_cntrl);
> break;
> + case DEV_ST_TRANSITION_FP:
> + write_lock_irq(&mhi_cntrl->pm_lock);
> + mhi_cntrl->ee = MHI_EE_FP;
> + write_unlock_irq(&mhi_cntrl->pm_lock);
> + mhi_create_devices(mhi_cntrl);
> + break;
> case DEV_ST_TRANSITION_READY:
> mhi_ready_state_transition(mhi_cntrl);
> break;
> @@ -1077,10 +1083,15 @@ int mhi_sync_power_up(struct mhi_controller
> *mhi_cntrl)
>
> wait_event_timeout(mhi_cntrl->state_event,
> MHI_IN_MISSION_MODE(mhi_cntrl->ee) ||
> + mhi_cntrl->ee == MHI_EE_FP ||
> MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
> msecs_to_jiffies(mhi_cntrl->timeout_ms));
>
> - ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;
> + if (mhi_cntrl->ee == MHI_EE_FP)
> + mhi_queue_state_transition(mhi_cntrl,
DEV_ST_TRANSITION_READY);
> + else
> + ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;
> +
> if (ret)
> mhi_power_down(mhi_cntrl, false);
>
We should come up with a better design for this later on.
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h index
> 6e1122c..4620af8 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -120,6 +120,7 @@ struct mhi_link_info {
> * @MHI_EE_WFW: WLAN firmware mode
> * @MHI_EE_PTHRU: Passthrough
> * @MHI_EE_EDL: Embedded downloader
> + * @MHI_EE_FP, Flash Programmer Environment
> */
> enum mhi_ee_type {
> MHI_EE_PBL,
> @@ -129,7 +130,8 @@ enum mhi_ee_type {
> MHI_EE_WFW,
> MHI_EE_PTHRU,
> MHI_EE_EDL,
> - MHI_EE_MAX_SUPPORTED = MHI_EE_EDL,
> + MHI_EE_FP,
> + MHI_EE_MAX_SUPPORTED = MHI_EE_FP,
> MHI_EE_DISABLE_TRANSITION, /* local EE, not related to mhi spec */
> MHI_EE_NOT_SUPPORTED,
> MHI_EE_MAX,

Thanks,
Bhaumik
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a
Linux Foundation Collaborative Project

Thanks,
Bhaumik
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project