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SubjectRe: [PATCH v4 5/5] remoteproc: qcom: Always assert and deassert reset signals in SDM845
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Hi Bjorn,
Thanks for the review. Will make all the required changes in v5.

On 05/19/2018 03:17 AM, Bjorn Andersson wrote:
> On Wed 25 Apr 08:08 PDT 2018, Sibi Sankar wrote:
>
>> SDM845 brings a new reset signal ALT_RESET which is a part of the MSS
>> subsystem hence requires some of the active clks to be enabled before
>> assert/deassert
>>
>> Reset the modem if the BOOT FSM does timeout
>>
>> Reset assert/deassert sequence vary across SoCs adding reset, adding
>> start/stop helper functions to handle SoC specific reset sequences
>>
>> Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
>> ---
>> drivers/remoteproc/qcom_q6v5_pil.c | 81 ++++++++++++++++++++++++++++--
>> 1 file changed, 76 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/remoteproc/qcom_q6v5_pil.c b/drivers/remoteproc/qcom_q6v5_pil.c
> [..]
>> @@ -349,6 +356,32 @@ static int q6v5_load(struct rproc *rproc, const struct firmware *fw)
>> return 0;
>> }
>>
>> +static int q6v5_reset_assert(struct q6v5 *qproc)
>> +{
>> + return reset_control_assert(qproc->mss_restart);
>> +}
>> +
>> +static int q6v5_reset_deassert(struct q6v5 *qproc)
>> +{
>> + return reset_control_deassert(qproc->mss_restart);
>> +}
>> +
>> +static int q6v5_alt_reset_assert(struct q6v5 *qproc)
>> +{
>> + return reset_control_reset(qproc->mss_restart);
>> +}
>> +
>> +static int q6v5_alt_reset_deassert(struct q6v5 *qproc)
>> +{
>> + /* Ensure alt reset is written before restart reg */
>> + writel(1, qproc->rmb_base + RMB_MBA_ALT_RESET);
>> +
>> + reset_control_reset(qproc->mss_restart);
>> +
>> + writel(0, qproc->rmb_base + RMB_MBA_ALT_RESET);
>> + return 0;
>> +}
>> +
>
> Rather than having these four functions and scattering jumps to some
> function pointer in the code I think it will be shorter and cleaner to
> just have the q6v5_reset_{asert,deassert}() functions and in there check
> if has_alt_reset and take appropriate action.
>

yes this seems simpler

>> static int q6v5_rmb_pbl_wait(struct q6v5 *qproc, int ms)
>> {
>> unsigned long timeout;
>> @@ -424,6 +457,8 @@ static int q6v5proc_reset(struct q6v5 *qproc)
>> val, (val & BIT(0)) != 0, 10, BOOT_FSM_TIMEOUT);
>> if (ret) {
>> dev_err(qproc->dev, "Boot FSM failed to complete.\n");
>> + /* Reset the modem so that boot FSM is in reset state */
>> + qproc->reset_deassert(qproc);
>
>
> A thing like this typically should go into it's own patch, to keep a
> clear record of why it was changed, but as this is simply amending the
> previous patch it indicates that that one wasn't complete.
>
> So if you reorder the two patches you can just put this directly into
> the sdm845 patch, making it "complete".
>
> (This also means that I want to merge the handover vs ready interrupt
> patch before that one, so please include it in the next revision of the
> series).
>

Will re-order them.


>> return ret;
>> }
>>
>> @@ -792,12 +827,20 @@ static int q6v5_start(struct rproc *rproc)
>> dev_err(qproc->dev, "failed to enable supplies\n");
>> goto disable_proxy_clk;
>> }
>> - ret = reset_control_deassert(qproc->mss_restart);
>> +
>> + ret = q6v5_clk_enable(qproc->dev, qproc->reset_clks,
>> + qproc->reset_clk_count);
>
> Remind me, why can't you always enable the active clock before
> deasserting reset? That way we wouldn't have to split out the iface
> clock handling to be just slightly longer than the active clocks.
>

Have to introduce reset clks for backward compatibility, both msm8916
and msm8996 require the mss_reset to be deasserted before enabling
the active clks.

>> if (ret) {
>> - dev_err(qproc->dev, "failed to deassert mss restart\n");
>> + dev_err(qproc->dev, "failed to enable reset clocks\n");
>> goto disable_vdd;
>> }
>>
>> + ret = qproc->reset_deassert(qproc);
>> + if (ret) {
>> + dev_err(qproc->dev, "failed to deassert mss restart\n");
>> + goto disable_reset_clks;
>> + }
>> +
> [..]
>> @@ -1335,8 +1399,11 @@ static const struct rproc_hexagon_res sdm845_mss = {
>> "prng",
>> NULL
>> },
>> - .active_clk_names = (char*[]){
>> + .reset_clk_names = (char*[]){
>> "iface",
>> + NULL
>> + },
>> + .active_clk_names = (char*[]){
>
> Again, if you reorder your patches to first add the support for
> alt_reset and then introduce sdm845 you don't need to modify the
> previous patch directly to make it work.
>

yeah I'll re-order them

>> "bus",
>> "mem",
>> "gpll0_mss",
>
> Regards,
> Bjorn
>

--
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc, is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

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