github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-23 13:14:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

bus: mhi: core: Fix sys error transition latency

Browse Source 
Bring forward the idea to fix the power down latency in
mhi_pm_disable_transition() further to mhi_pm_sys_error_transition()
so that the transition into system error (triggered by AT!RESET) in the
modems won't have to return only after the timeout of up to 24 seconds.

Once the device gets reset, there is no guarantee that it will send an
interrupt to indicate the state transition. So polling is the sensible
option here.

Signed-off-by: Qingtao Cao <qingtao.cao.au@gmail.com>
[mani: commit log]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Link: https://patch.msgid.link/20260603011333.3306102-2-qingtao.cao.au@gmail.com
This commit is contained in:
Qingtao Cao 2026-06-03 11:06:11 +10:00 committed by Manivannan Sadhasivam
parent dc59e4fea9
commit 22568e8f13
1 changed files with 3 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/bus/mhi/host/pm.c
View File

@ -651,21 +651,13 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
/* Trigger MHI RESET so that the device will not access host memory */
if (reset_device) {
u32 in_reset = -1;
unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
dev_dbg(dev, "Triggering MHI Reset in device\n");
mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
/* Wait for the reset bit to be cleared by the device */
ret = wait_event_timeout(mhi_cntrl->state_event,
mhi_read_reg_field(mhi_cntrl,
mhi_cntrl->regs,
MHICTRL,
MHICTRL_RESET_MASK,
&in_reset) ||
!in_reset, timeout);
if (!ret || in_reset) {
ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
MHICTRL_RESET_MASK, 0, 25000, mhi_cntrl->timeout_ms);
if (ret) {
dev_err(dev, "Device failed to exit MHI Reset state\n");
write_lock_irq(&mhi_cntrl->pm_lock);
cur_state = mhi_tryset_pm_state(mhi_cntrl,