Re: [PATCH 1/1] bus: mhi: host: don't free bhie tables during power off

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

Hi Krishna,

Thank you for reviewing.

On 4/9/25 4:25 PM, Krishna Chaitanya Chundru wrote:
> 
> 
> On 4/9/2025 1:54 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. Use the same allocated
>> memory again and again after every resume/hibernation. This patch has
>> been tested with resume and hibernation both.
> How do you handle the mhi un-register case, in that case all the MHI
> memory needs to be freed.
I'm working on fixing it. I'll post a v2.

>>
>> 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>
>> ---
>>   drivers/bus/mhi/host/boot.c | 11 +++++++----
>>   drivers/bus/mhi/host/init.c | 15 +++------------
>>   2 files changed, 10 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
>> index efa3b6dddf4d2..8b3d2b9d239c3 100644
>> --- a/drivers/bus/mhi/host/boot.c
>> +++ b/drivers/bus/mhi/host/boot.c
>> @@ -323,6 +323,7 @@ void mhi_free_bhie_table(struct mhi_controller
>> *mhi_cntrl,
>>                     mhi_buf->buf, mhi_buf->dma_addr);
>>         kfree(image_info->mhi_buf);
>> +    image_info->mhi_buf = NULL;
> image_info is getting freed in the next line. why do we need this?
I'll remove this line.

> 
> - Krishna Chaitanya.
>>       kfree(image_info);
>>   }
>>   @@ -584,10 +585,12 @@ void mhi_fw_load_handler(struct mhi_controller
>> *mhi_cntrl)
>>        * device transitioning into MHI READY state
>>        */
>>       if (fw_load_type == MHI_FW_LOAD_FBC) {
>> -        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) {
>> +            ret = mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl-
>> >fbc_image, fw_sz);
>> +            if (ret) {
>> +                release_firmware(firmware);
>> +                goto error_fw_load;
>> +            }
>>           }
>>             /* Load the firmware into BHIE vec table */
>> diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
>> index 13e7a55f54ff4..3c20e4541357e 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);
>> @@ -1202,16 +1203,6 @@ EXPORT_SYMBOL_GPL(mhi_prepare_for_power_up);
>>     void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
>>   {
>> -    if (mhi_cntrl->fbc_image) {
>> -        mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
>> -        mhi_cntrl->fbc_image = NULL;
>> -    }
>> -
>> -    if (mhi_cntrl->rddm_image) {
>> -        mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
>> -        mhi_cntrl->rddm_image = NULL;
>> -    }
>> -
>>       mhi_cntrl->bhi = NULL;
>>       mhi_cntrl->bhie = NULL;
>>   


-- 
Regards,
Usama