The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 1d1493bdc25f498468a606a4ece947d155cfa3a9 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023050652-balancing-evasive-6713@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 1d1493bdc25f ("bus: mhi: host: Use mhi_tryset_pm_state() for setting fw error state") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1d1493bdc25f498468a606a4ece947d155cfa3a9 Mon Sep 17 00:00:00 2001 From: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx> Date: Mon, 10 Apr 2023 09:58:12 -0600 Subject: [PATCH] bus: mhi: host: Use mhi_tryset_pm_state() for setting fw error state If firmware loading fails, the controller's pm_state is updated to MHI_PM_FW_DL_ERR unconditionally. This can corrupt the pm_state as the update is not done under the proper lock, and also does not validate the state transition. The firmware loading can fail due to a detected syserr, but if MHI_PM_FW_DL_ERR is unconditionally set as the pm_state, the handling of the syserr can break when it attempts to transition from syserr detect, to syserr process. By grabbing the lock, we ensure we don't race with some other pm_state update. By using mhi_try_set_pm_state(), we check that the transition to MHI_PM_FW_DL_ERR is valid via the state machine logic. If it is not valid, then some other transition is occurring like syserr processing, and we assume that will resolve the firmware loading error. Fixes: 12e050c77be0 ("bus: mhi: core: Move to an error state on any firmware load failure") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx> Reviewed-by: Carl Vanderlip <quic_carlv@xxxxxxxxxxx> Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx> Link: https://lore.kernel.org/r/1681142292-27571-3-git-send-email-quic_jhugo@xxxxxxxxxxx Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c index 1c69feee1703..d2a19b07ccb8 100644 --- a/drivers/bus/mhi/host/boot.c +++ b/drivers/bus/mhi/host/boot.c @@ -391,6 +391,7 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) { const struct firmware *firmware = NULL; struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_pm_state new_state; const char *fw_name; void *buf; dma_addr_t dma_addr; @@ -508,14 +509,18 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) } error_fw_load: - mhi_cntrl->pm_state = MHI_PM_FW_DL_ERR; - wake_up_all(&mhi_cntrl->state_event); + write_lock_irq(&mhi_cntrl->pm_lock); + new_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_FW_DL_ERR); + write_unlock_irq(&mhi_cntrl->pm_lock); + if (new_state == MHI_PM_FW_DL_ERR) + wake_up_all(&mhi_cntrl->state_event); } int mhi_download_amss_image(struct mhi_controller *mhi_cntrl) { struct image_info *image_info = mhi_cntrl->fbc_image; struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_pm_state new_state; int ret; if (!image_info) @@ -526,8 +531,11 @@ int mhi_download_amss_image(struct mhi_controller *mhi_cntrl) &image_info->mhi_buf[image_info->entries - 1]); if (ret) { dev_err(dev, "MHI did not load AMSS, ret:%d\n", ret); - mhi_cntrl->pm_state = MHI_PM_FW_DL_ERR; - wake_up_all(&mhi_cntrl->state_event); + write_lock_irq(&mhi_cntrl->pm_lock); + new_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_FW_DL_ERR); + write_unlock_irq(&mhi_cntrl->pm_lock); + if (new_state == MHI_PM_FW_DL_ERR) + wake_up_all(&mhi_cntrl->state_event); } return ret;
