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

[Muhammad Usama Anjum <usama.anjum@collabora.com>]

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?

> 
> - 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
>>
>>


-- 
Regards,
Usama