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

From: Krishna Chaitanya Chundru
Date: Thu Apr 10 2025 - 23:38:18 EST



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 ?
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@xxxxxxxxxxxxx>
---
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