[PATCH 3/3] bus: mhi: keep device context through suspend cycles

From: Muhammad Usama Anjum
Date: Mon Jun 30 2025 - 03:46:36 EST


Don't deinitialize the device context while going into suspend or
hibernation cycles. Otherwise the resume may fail if at resume time, the
memory pressure is high and no dma memory is available.

Tested-on: WCN6855 WLAN.HSP.1.1-03926.13-QCAHSPSWPL_V2_SILICONZ_CE-2.52297.6

Fixes: 3000f85b8f47 ("bus: mhi: core: Add support for basic PM operations")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
---
drivers/bus/mhi/host/init.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index 2e0f18c939e68..8f56e73fdc42e 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -1133,9 +1133,11 @@ int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)

mutex_lock(&mhi_cntrl->pm_mutex);

- ret = mhi_init_dev_ctxt(mhi_cntrl);
- if (ret)
- goto error_dev_ctxt;
+ if (!mhi_cntrl->mhi_ctxt) {
+ ret = mhi_init_dev_ctxt(mhi_cntrl);
+ if (ret)
+ goto error_dev_ctxt;
+ }

ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIOFF, &bhi_off);
if (ret) {
@@ -1212,8 +1214,6 @@ void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl)
{
mhi_cntrl->bhi = NULL;
mhi_cntrl->bhie = NULL;
-
- __mhi_deinit_dev_ctxt(mhi_cntrl);
}

void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
@@ -1234,6 +1234,7 @@ void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
}

mhi_deinit_dev_ctxt(mhi_cntrl);
+ __mhi_deinit_dev_ctxt(mhi_cntrl);
}
EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);

--
2.39.5