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

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Date:   Wed,  2 Dec 2020 15:11:42 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
To:     gregkh@...uxfoundation.org
Cc:     hemantk@...eaurora.org, bbhatt@...eaurora.org,
        linux-arm-msm@...r.kernel.org, jhugo@...eaurora.org,
        linux-kernel@...r.kernel.org, loic.poulain@...aro.org,
        Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Subject: [PATCH 12/29] bus: mhi: core: Skip RDDM download for unknown execution environment

From: Bhaumik Bhatt <bbhatt@...eaurora.org>

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@...eaurora.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@...eaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
---
 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