summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLoic Poulain <loic.poulain@linaro.org>2021-02-23 16:42:20 +0100
committerLoic Poulain <loic.poulain@linaro.org>2021-03-05 13:30:42 +0100
commit83127a9a50e6b146c367a60727972f0334bc4a52 (patch)
tree65d0975ceb2db5de1b8b3b43992a682c4a3d06d7
parente36d9149f9c701da479b28b09490b9186109bbca (diff)
mhi: pci_generic: No-Op for device_wake operations
The wake_db register presence is highly speculative and can fuze MHI devices. Indeed, currently the wake_db register address is defined at entry 127 of the 'Channel doorbell array', thus writing to this address is equivalent to ringing the doorbell for channel 127, causing trouble with some devics (e.g. SDX24 based modems) that get an unexpected channel 127 doorbell interrupt. This change fixes that issue by setting wake get/put as no-op for pci_generic devices. The wake device sideband mechanism seems really specific to each device, and is AFAIK not defined by the MHI spec. It also removes zeroing initialization of wake_db register during MMIO initialization, the register being set via wake_get/put accessors few cycles later during M0 transition. Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
-rw-r--r--drivers/bus/mhi/core/init.c2
-rw-r--r--drivers/bus/mhi/pci_generic.c18
2 files changed, 18 insertions, 2 deletions
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 2159dbc6c2bf..32eb90fd8470 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -510,8 +510,6 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
/* Setup wake db */
mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
- mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 4, 0);
- mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 0, 0);
mhi_cntrl->wake_set = false;
/* Setup channel db address for each channel in tre_ring */
diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
index c274e65ca84e..4685a8325249 100644
--- a/drivers/bus/mhi/pci_generic.c
+++ b/drivers/bus/mhi/pci_generic.c
@@ -312,6 +312,21 @@ static void mhi_pci_status_cb(struct mhi_controller *mhi_cntrl,
}
}
+static void mhi_pci_wake_get_nop(struct mhi_controller *mhi_cntrl, bool force)
+{
+ /* no-op */
+}
+
+static void mhi_pci_wake_put_nop(struct mhi_controller *mhi_cntrl, bool override)
+{
+ /* no-op */
+}
+
+static void mhi_pci_wake_toggle_nop(struct mhi_controller *mhi_cntrl)
+{
+ /* no-op */
+}
+
static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl)
{
struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
@@ -515,6 +530,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
mhi_cntrl->status_cb = mhi_pci_status_cb;
mhi_cntrl->runtime_get = mhi_pci_runtime_get;
mhi_cntrl->runtime_put = mhi_pci_runtime_put;
+ mhi_cntrl->wake_get = mhi_pci_wake_get_nop;
+ mhi_cntrl->wake_put = mhi_pci_wake_put_nop;
+ mhi_cntrl->wake_toggle = mhi_pci_wake_toggle_nop;
err = mhi_pci_claim(mhi_cntrl, info->bar_num, DMA_BIT_MASK(info->dma_data_width));
if (err)