[PATCH 12/29] bus: mhi: core: Skip RDDM download for unknown execution environment

From: Manivannan Sadhasivam
Date: Wed Dec 02 2020 - 04:45:36 EST


From: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>

If MHI is unable to determine the execution environment during
the panic path, host must skip the RDDM download. This can happen
if the BHI offset read or the BHI_EXECENV register read fails
indicating that the underlying transport is unresponsive. Hence,
there is no need to trigger an RDDM using SYSERR or request an
SOC reset.

Suggested-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx>
Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
drivers/bus/mhi/core/boot.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
index 16244cc8fbe7..6f0cfb9922b4 100644
--- a/drivers/bus/mhi/core/boot.c
+++ b/drivers/bus/mhi/core/boot.c
@@ -92,6 +92,9 @@ static int __mhi_download_rddm_in_panic(struct mhi_controller *mhi_cntrl)
* image download completion.
*/
ee = mhi_get_exec_env(mhi_cntrl);
+ if (ee == MHI_EE_MAX)
+ goto error_exit_rddm;
+
if (ee != MHI_EE_RDDM) {
dev_dbg(dev, "Trigger device into RDDM mode using SYS ERR\n");
mhi_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR);
@@ -139,10 +142,12 @@ static int __mhi_download_rddm_in_panic(struct mhi_controller *mhi_cntrl)
ee = mhi_get_exec_env(mhi_cntrl);
ret = mhi_read_reg(mhi_cntrl, base, BHIE_RXVECSTATUS_OFFS, &rx_status);

- dev_err(dev, "Did not complete RDDM transfer\n");
- dev_err(dev, "Current EE: %s\n", TO_MHI_EXEC_STR(ee));
dev_err(dev, "RXVEC_STATUS: 0x%x\n", rx_status);

+error_exit_rddm:
+ dev_err(dev, "RDDM transfer failed. Current EE: %s\n",
+ TO_MHI_EXEC_STR(ee));
+
return -EIO;
}

--
2.25.1