Re: [PATCH v2] bus: mhi: host: don't free bhie tables during suspend/hibernation

[Krishna Chaitanya Chundru <quic_krichai@quicinc.com>]

On 4/12/2025 12:02 AM, Muhammad Usama Anjum wrote:
> On 4/11/25 1:39 PM, Krishna Chaitanya Chundru wrote:
>>
>>
>> On 4/11/2025 12:32 PM, Muhammad Usama Anjum wrote:
>>> On 4/11/25 8:37 AM, Krishna Chaitanya Chundru wrote:
>>>>
>>>>
>>>> On 4/10/2025 8:26 PM, Muhammad Usama Anjum wrote:
>>>>> Fix dma_direct_alloc() failure at resume time during bhie_table
>>>>> allocation. There is a crash report where at resume time, the memory
>>>>> from the dma doesn't get allocated and MHI fails to re-initialize.
>>>>> There may be fragmentation of some kind which fails the allocation
>>>>> call.
>>>>>
>>>>> To fix it, don't free the memory at power down during suspend /
>>>>> hibernation. Instead, use the same allocated memory again after every
>>>>> resume / hibernation. This patch has been tested with resume and
>>>>> hibernation both.
>>>>>
>>>>> The rddm is of constant size for a given hardware. While the fbc_image
>>>>> size depends on the firmware. If the firmware changes, we'll free and
>>>> If firmware image will change between suspend and resume ?
>>> Yes, correct.
>>>
>> why the firmware image size will change between suspend & resume?
>> who will update the firmware image after bootup?
>> It is not expected behaviour.
> I was trying to research if the firmware can change or not. I've not
> found any documentation on it.
> 
> If the firmare is updated in filesystem before suspend/hibernate, would
> the new firwmare be loaded the next time kernel resumes as the older
> firmware is no where to be found?
> 
> What do you think about this?
> 
I don't think firmware can be updated before suspend/hibernate. I don't
see any reason why it can be updated. If you think it can be updated
please quote relevant doc.

- Krishna Chaitanya.
>>
>> - Krishna chaitanya.
>>>>> allocate new memory for it.
>>>>>
>>>>> Here are the crash logs:
>>>>>
>>>>> [ 3029.338587] mhi mhi0: Requested to power ON
>>>>> [ 3029.338621] mhi mhi0: Power on setup success
>>>>> [ 3029.668654] kworker/u33:8: page allocation failure: order:7,
>>>>> mode:0xc04(GFP_NOIO|GFP_DMA32), nodemask=(null),cpuset=/,mems_allowed=0
>>>>> [ 3029.668682] CPU: 4 UID: 0 PID: 2744 Comm: kworker/u33:8 Not tainted
>>>>> 6.11.11-valve10-1-neptune-611-gb69e902b4338
>>>>> #1ed779c892334112fb968aaa3facf9686b5ff0bd7
>>>>> [ 3029.668690] Hardware name: Valve Galileo/Galileo, BIOS F7G0112
>>>>> 08/01/2024
>>>>> [ 3029.668694] Workqueue: mhi_hiprio_wq mhi_pm_st_worker [mhi]
>>>>> [ 3029.668717] Call Trace:
>>>>> [ 3029.668722]  <TASK>
>>>>> [ 3029.668728]  dump_stack_lvl+0x4e/0x70
>>>>> [ 3029.668738]  warn_alloc+0x164/0x190
>>>>> [ 3029.668747]  ? srso_return_thunk+0x5/0x5f
>>>>> [ 3029.668754]  ? __alloc_pages_direct_compact+0xaf/0x360
>>>>> [ 3029.668761]  __alloc_pages_slowpath.constprop.0+0xc75/0xd70
>>>>> [ 3029.668774]  __alloc_pages_noprof+0x321/0x350
>>>>> [ 3029.668782]  __dma_direct_alloc_pages.isra.0+0x14a/0x290
>>>>> [ 3029.668790]  dma_direct_alloc+0x70/0x270
>>>>> [ 3029.668796]  mhi_alloc_bhie_table+0xe8/0x190 [mhi
>>>>> faa917c5aa23a5f5b12d6a2c597067e16d2fedc0]
>>>>> [ 3029.668814]  mhi_fw_load_handler+0x1bc/0x310 [mhi
>>>>> faa917c5aa23a5f5b12d6a2c597067e16d2fedc0]
>>>>> [ 3029.668830]  mhi_pm_st_worker+0x5c8/0xaa0 [mhi
>>>>> faa917c5aa23a5f5b12d6a2c597067e16d2fedc0]
>>>>> [ 3029.668844]  ? srso_return_thunk+0x5/0x5f
>>>>> [ 3029.668853]  process_one_work+0x17e/0x330
>>>>> [ 3029.668861]  worker_thread+0x2ce/0x3f0
>>>>> [ 3029.668868]  ? __pfx_worker_thread+0x10/0x10
>>>>> [ 3029.668873]  kthread+0xd2/0x100
>>>>> [ 3029.668879]  ? __pfx_kthread+0x10/0x10
>>>>> [ 3029.668885]  ret_from_fork+0x34/0x50
>>>>> [ 3029.668892]  ? __pfx_kthread+0x10/0x10
>>>>> [ 3029.668898]  ret_from_fork_asm+0x1a/0x30
>>>>> [ 3029.668910]  </TASK>
>>>>>
>>>>> Tested-on: QCNFA765 WLAN.HSP.1.1-03926.13-
>>>>> QCAHSPSWPL_V2_SILICONZ_CE-2.52297.6
>>>>>
>>>>> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
>>>>> ---
>>>>> Changes sice v1:
>>>>> - Don't free bhie tables during suspend/hibernation only
>>>>> - Handle fbc_image changed size correctly
>>>>> - Remove fbc_image getting set to NULL in *free_bhie_table()
>>>>> ---
>>>>>     drivers/bus/mhi/host/boot.c           | 15 +++++++++++----
>>>>>     drivers/bus/mhi/host/init.c           | 13 ++++++++++---
>>>>>     drivers/net/wireless/ath/ath11k/mhi.c |  9 +++++----
>>>>>     include/linux/mhi.h                   |  7 +++++++
>>>>>     4 files changed, 33 insertions(+), 11 deletions(-)
>>>>>
>>>>> diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
>>>>> index 9dcc7184817d5..0df26100c8f9c 100644
>>>>> --- a/drivers/bus/mhi/host/boot.c
>>>>> +++ b/drivers/bus/mhi/host/boot.c
>>>>> @@ -487,10 +487,17 @@ void mhi_fw_load_handler(struct mhi_controller
>>>>> *mhi_cntrl)
>>>>>          * device transitioning into MHI READY state
>>>>>          */
>>>>>         if (mhi_cntrl->fbc_download) {
>>>>> -        ret = mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->fbc_image,
>>>>> fw_sz);
>>>>> -        if (ret) {
>>>>> -            release_firmware(firmware);
>>>>> -            goto error_fw_load;
>>>>> +        if (mhi_cntrl->fbc_image && fw_sz != mhi_cntrl->prev_fw_sz) {
>>>>> +            mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
>>>>> +            mhi_cntrl->fbc_image = NULL;
>>>>> +        }
>>>>> +        if (!mhi_cntrl->fbc_image) {
>>>>> +            ret = mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl-
>>>>>> fbc_image, fw_sz);
>>>>> +            if (ret) {
>>>>> +                release_firmware(firmware);
>>>>> +                goto error_fw_load;
>>>>> +            }
>>>>> +            mhi_cntrl->prev_fw_sz = fw_sz;
>>>>>             }
>>>>>               /* Load the firmware into BHIE vec table */
>>>>> diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
>>>>> index a9b1f8beee7bc..09b946b86ac46 100644
>>>>> --- a/drivers/bus/mhi/host/init.c
>>>>> +++ b/drivers/bus/mhi/host/init.c
>>>>> @@ -1173,8 +1173,9 @@ int mhi_prepare_for_power_up(struct
>>>>> mhi_controller *mhi_cntrl)
>>>>>             /*
>>>>>              * Allocate RDDM table for debugging purpose if specified
>>>>>              */
>>>>> -        mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
>>>>> -                     mhi_cntrl->rddm_size);
>>>>> +        if (!mhi_cntrl->rddm_image)
>>>>> +            mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
>>>>> +                         mhi_cntrl->rddm_size);
>>>>>             if (mhi_cntrl->rddm_image) {
>>>>>                 ret = mhi_rddm_prepare(mhi_cntrl,
>>>>>                                mhi_cntrl->rddm_image);
>>>>> @@ -1212,12 +1213,18 @@ void mhi_unprepare_after_power_down(struct
>>>>> mhi_controller *mhi_cntrl)
>>>>>             mhi_cntrl->rddm_image = NULL;
>>>>>         }
>>>>>     +    mhi_partial_unprepare_after_power_down(mhi_cntrl);
>>>>> +}
>>>>> +EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
>>>>> +
>>>>> +void mhi_partial_unprepare_after_power_down(struct mhi_controller
>>>>> *mhi_cntrl)
>>>>> +{
>>>>>         mhi_cntrl->bhi = NULL;
>>>>>         mhi_cntrl->bhie = NULL;
>>>>>           mhi_deinit_dev_ctxt(mhi_cntrl);
>>>>>     }
>>>>> -EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
>>>>> +EXPORT_SYMBOL_GPL(mhi_partial_unprepare_after_power_down);
>>>>>     
>>>> Instead of adding new API you can free memory from the unregister
>>>> controller also.
>>>>
>>>> - Krishna Chaitanya.
>>>>>     static void mhi_release_device(struct device *dev)
>>>>>     {
>>>>> diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/
>>>>> wireless/ath/ath11k/mhi.c
>>>>> index acd76e9392d31..f77cec79b5b80 100644
>>>>> --- a/drivers/net/wireless/ath/ath11k/mhi.c
>>>>> +++ b/drivers/net/wireless/ath/ath11k/mhi.c
>>>>> @@ -460,12 +460,13 @@ void ath11k_mhi_stop(struct ath11k_pci *ab_pci,
>>>>> bool is_suspend)
>>>>>          * workaround, otherwise ath11k_core_resume() will timeout
>>>>>          * during resume.
>>>>>          */
>>>>> -    if (is_suspend)
>>>>> +    if (is_suspend) {
>>>>>             mhi_power_down_keep_dev(ab_pci->mhi_ctrl, true);
>>>>> -    else
>>>>> +        mhi_partial_unprepare_after_power_down(ab_pci->mhi_ctrl);
>>>>> +    } else {
>>>>>             mhi_power_down(ab_pci->mhi_ctrl, true);
>>>>> -
>>>>> -    mhi_unprepare_after_power_down(ab_pci->mhi_ctrl);
>>>>> +        mhi_unprepare_after_power_down(ab_pci->mhi_ctrl);
>>>>> +    }
>>>>>     }
>>>>>       int ath11k_mhi_suspend(struct ath11k_pci *ab_pci)
>>>>> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
>>>>> index 059dc94d20bb6..65a47c712b3a0 100644
>>>>> --- a/include/linux/mhi.h
>>>>> +++ b/include/linux/mhi.h
>>>>> @@ -382,6 +382,7 @@ struct mhi_controller {
>>>>>         const char *fw_image;
>>>>>         const u8 *fw_data;
>>>>>         size_t fw_sz;
>>>>> +    size_t prev_fw_sz;
>>>>>         const char *edl_image;
>>>>>         size_t rddm_size;
>>>>>         size_t sbl_size;
>>>>> @@ -662,6 +663,12 @@ void mhi_power_down_keep_dev(struct
>>>>> mhi_controller *mhi_cntrl, bool graceful);
>>>>>      */
>>>>>     void mhi_unprepare_after_power_down(struct mhi_controller
>>>>> *mhi_cntrl);
>>>>>     +/**
>>>>> + * mhi_partial_unprepare_after_power_down - Free any allocated memory
>>>>> after power down partially
>>>>> + * @mhi_cntrl: MHI controller
>>>>> + */
>>>>> +void mhi_partial_unprepare_after_power_down(struct mhi_controller
>>>>> *mhi_cntrl);
>>>>> +
>>>>>     /**
>>>>>      * mhi_pm_suspend - Move MHI into a suspended state
>>>>>      * @mhi_cntrl: MHI controller
>>>
>>>
> 
>