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| author | Sibi Sankar <sibis@codeaurora.org> | 2020-01-23 18:42:36 +0530 |
|---|---|---|
| committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2020-01-24 09:34:07 -0800 |
| commit | 600c39b34369e2a1bf78eb67afb99ce550f271cc (patch) | |
| tree | da3188db40316d35a02613d8bf6559092adae2ad /drivers/remoteproc/qcom_q6v5_mss.c | |
| parent | 01bf3fec38e9188846f6755cd29da515f5852bc5 (diff) | |
| download | lwn-600c39b34369e2a1bf78eb67afb99ce550f271cc.tar.gz lwn-600c39b34369e2a1bf78eb67afb99ce550f271cc.zip | |
remoteproc: qcom: q6v5-mss: Improve readability of reset_assert
Define AXI_GATING_VALID_OVERRIDE and fixup comments to improve readability
of Q6 modem reset sequence on SC7180 SoCs.
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20200123131236.1078-3-sibis@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/remoteproc/qcom_q6v5_mss.c')
| -rw-r--r-- | drivers/remoteproc/qcom_q6v5_mss.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c index 89ab96c21a44..a1cc9cbe038f 100644 --- a/drivers/remoteproc/qcom_q6v5_mss.c +++ b/drivers/remoteproc/qcom_q6v5_mss.c @@ -71,6 +71,7 @@ #define NAV_AXI_HALTREQ_BIT BIT(0) #define NAV_AXI_HALTACK_BIT BIT(1) #define NAV_AXI_IDLE_BIT BIT(2) +#define AXI_GATING_VALID_OVERRIDE BIT(0) #define HALT_ACK_TIMEOUT_US 100000 #define NAV_HALT_ACK_TIMEOUT_US 200 @@ -415,16 +416,24 @@ static int q6v5_reset_assert(struct q6v5 *qproc) ret = reset_control_reset(qproc->mss_restart); reset_control_deassert(qproc->pdc_reset); } else if (qproc->has_halt_nav) { - /* SWAR using CONN_BOX_SPARE_0 for pipeline glitch issue */ + /* + * When the AXI pipeline is being reset with the Q6 modem partly + * operational there is possibility of AXI valid signal to + * glitch, leading to spurious transactions and Q6 hangs. A work + * around is employed by asserting the AXI_GATING_VALID_OVERRIDE + * BIT before triggering Q6 MSS reset. Both the HALTREQ and + * AXI_GATING_VALID_OVERRIDE are withdrawn post MSS assert + * followed by a MSS deassert, while holding the PDC reset. + */ reset_control_assert(qproc->pdc_reset); regmap_update_bits(qproc->conn_map, qproc->conn_box, - BIT(0), BIT(0)); + AXI_GATING_VALID_OVERRIDE, 1); regmap_update_bits(qproc->halt_nav_map, qproc->halt_nav, NAV_AXI_HALTREQ_BIT, 0); reset_control_assert(qproc->mss_restart); reset_control_deassert(qproc->pdc_reset); regmap_update_bits(qproc->conn_map, qproc->conn_box, - BIT(0), 0); + AXI_GATING_VALID_OVERRIDE, 0); ret = reset_control_deassert(qproc->mss_restart); } else { ret = reset_control_assert(qproc->mss_restart); |