Messages in this thread | | | Subject | Re: [PATCH v3 7/7] remoteproc: qcom: Always assert and deassert reset signals in SDM845 | From | Sibi S <> | Date | Fri, 23 Mar 2018 03:40:17 +0530 |
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Hi Bjorn, Thanks for the review
On 03/19/2018 04:16 AM, Bjorn Andersson wrote: > On Wed 14 Mar 02:21 PDT 2018, Sibi S wrote: >> diff --git a/drivers/remoteproc/qcom_q6v5_pil.c b/drivers/remoteproc/qcom_q6v5_pil.c > [..] >> +struct q6v5_reset_ops { >> + int (*reset_start)(struct q6v5 *qproc); >> + int (*reset_stop)(struct q6v5 *qproc); >> +}; > > Please add these two ops directly in q6v5 instead and please keep the > naming "reset_assert" and "reset_deassert". >
sure will do
>> + >> enum { >> MSS_MSM8916, >> MSS_MSM8974, >> @@ -343,6 +354,52 @@ static int q6v5_load(struct rproc *rproc, const struct firmware *fw) >> return 0; >> } >> >> +static void alt_reset_restart(struct q6v5 *qproc, u32 restart) >> +{ >> + writel(restart, qproc->rmb_base + RMB_MBA_ALT_RESET); > > Just move this write into q6v5_sdm_reset_start() >
sure will do
>> +} >> + >> +static int q6v5_msm_reset_stop(struct q6v5 *qproc) >> +{ >> + return reset_control_assert(qproc->mss_restart); >> +} >> + >> +static int q6v5_msm_reset_start(struct q6v5 *qproc) >> +{ >> + return reset_control_deassert(qproc->mss_restart); >> +} >> + >> +static int q6v5_sdm_reset_stop(struct q6v5 *qproc) >> +{ >> + return reset_control_reset(qproc->mss_restart); >> +} >> + >> +static int q6v5_sdm_reset_start(struct q6v5 *qproc) >> +{ >> + int ret; >> + >> + alt_reset_restart(qproc, 1); >> + /* Ensure alt reset is written before restart reg */ > > That's not what udelay does ;) > > If you want to make sure that the register is written and then give it > 100us delay until you reset the reset you have to readl() the same > register back after the writel() > > I think the delay deserves a comment on what we're waiting for. >
the delay can be removed for the reasons stated below
>> + udelay(100); > > Use usleep_range() for delays longer than 10us. > >> + >> + ret = reset_control_reset(qproc->mss_restart); >> + >> + udelay(100); > > Same as the delay above, what are we waiting for? >
The point is to wait for 6 32khz sleep cycles both after assert and after de-assert of the aoss mss reset line. So moving the udelay to the aoss reset controller should have been right thing to do. alt_reset shouldn't need delays in between will remove them.
>> + alt_reset_restart(qproc, 0); >> + >> + return ret; >> +} >> + > [..] >> @@ -1179,6 +1251,12 @@ static int q6v5_probe(struct platform_device *pdev) >> qproc->dev = &pdev->dev; >> qproc->rproc = rproc; >> platform_set_drvdata(pdev, qproc); >> + qproc->version = desc->version; >> + >> + if (qproc->version == MSS_SDM845) >> + qproc->ops = &q6v5_sdm_ops; >> + else >> + qproc->ops = &q6v5_msm_ops; > > Can we carry a boolean for "has_alt_reset" or something that picks the > new reset ops, rather than picking by version? >
Though alt_reset is specific to SDM845 SoCs it also includes another reset controller (pdc_sync) in the modem bringup sequence, it isn't included it in the patch series since it doesn't seem to affect the modem start/stop functionality. Knowing that it may be added wouldn't version be a better choice here?
> Regards, > Bjorn >
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