Messages in this thread | | | Date | Wed, 25 Mar 2020 16:56:37 +0800 | From | Can Guo <> | Subject | Re: [PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path |
| |
On 2020-03-18 16:19, Avri Altman wrote: > Hi, > >> >> From: Subhash Jadavani <subhashj@codeaurora.org> >> >> This change introduces a func ufshcd_set_clk_freq() to explicitly >> set clock frequency so that it can be used in reset_and_resotre path >> and >> in ufshcd_scale_clks(). Meanwhile, this change cleans up the clock >> scaling >> error out path. >> >> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> >> Signed-off-by: Can Guo <cang@codeaurora.org> >> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >> index 2a2a63b..63aaa88f 100644 >> --- a/drivers/scsi/ufs/ufshcd.c >> +++ b/drivers/scsi/ufs/ufshcd.c >> @@ -855,28 +855,29 @@ static bool >> ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba) >> return false; >> } >> >> -static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up) >> +/** >> + * ufshcd_set_clk_freq - set UFS controller clock frequencies >> + * @hba: per adapter instance >> + * @scale_up: If True, set max possible frequency othewise set low >> frequency >> + * >> + * Returns 0 if successful >> + * Returns < 0 for any other errors >> + */ >> +static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up) > Personally I prefer using the convention of "__scale_clks" to describe > the privet core of scale_clks, > But I know that many people are against it. > >> { >> int ret = 0; >> struct ufs_clk_info *clki; >> struct list_head *head = &hba->clk_list_head; >> - ktime_t start = ktime_get(); >> - bool clk_state_changed = false; >> >> if (list_empty(head)) >> goto out; >> >> - ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE); >> - if (ret) >> - return ret; >> - >> list_for_each_entry(clki, head, list) { >> if (!IS_ERR_OR_NULL(clki->clk)) { >> if (scale_up && clki->max_freq) { >> if (clki->curr_freq == clki->max_freq) >> continue; >> >> - clk_state_changed = true; >> ret = clk_set_rate(clki->clk, >> clki->max_freq); >> if (ret) { >> dev_err(hba->dev, "%s: %s clk >> set rate(%dHz) failed, >> %d\n", >> @@ -895,7 +896,6 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, >> bool scale_up) >> if (clki->curr_freq == clki->min_freq) >> continue; >> >> - clk_state_changed = true; >> ret = clk_set_rate(clki->clk, >> clki->min_freq); >> if (ret) { >> dev_err(hba->dev, "%s: %s clk >> set rate(%dHz) failed, >> %d\n", >> @@ -914,13 +914,36 @@ static int ufshcd_scale_clks(struct ufs_hba >> *hba, >> bool scale_up) >> clki->name, clk_get_rate(clki->clk)); >> } >> >> +out: >> + return ret; >> +} >> + >> +/** >> + * ufshcd_scale_clks - scale up or scale down UFS controller clocks >> + * @hba: per adapter instance >> + * @scale_up: True if scaling up and false if scaling down >> + * >> + * Returns 0 if successful >> + * Returns < 0 for any other errors >> + */ >> +static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up) >> +{ >> + int ret = 0; >> + >> + ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE); >> + if (ret) >> + return ret; >> + >> + ret = ufshcd_set_clk_freq(hba, scale_up); >> + if (ret) >> + return ret; >> + >> ret = ufshcd_vops_clk_scale_notify(hba, scale_up, >> POST_CHANGE); >> + if (ret) { >> + ufshcd_set_clk_freq(hba, !scale_up); >> + return ret; >> + } >> >> -out: >> - if (clk_state_changed) >> - trace_ufshcd_profile_clk_scaling(dev_name(hba->dev), >> - (scale_up ? "up" : "down"), >> - ktime_to_us(ktime_sub(ktime_get(), start)), >> ret); > > Why remove the ufshcd_profile_clk_scaling trace? > >
Shall add it back, this is just a collection of Subhash's changes.
>> return ret; >> } >> >> @@ -1106,35 +1129,36 @@ static int ufshcd_devfreq_scale(struct ufs_hba >> *hba, bool scale_up) >> >> ret = ufshcd_clock_scaling_prepare(hba); >> if (ret) >> - return ret; >> + goto out; > Are you fixing here a hold without release? > Should make note of that. >
Yes, true
>> >> /* scale down the gear before scaling down clocks */ >> if (!scale_up) { >> ret = ufshcd_scale_gear(hba, false); >> if (ret) >> - goto out; >> + goto clk_scaling_unprepare; >> } >> >> ret = ufshcd_scale_clks(hba, scale_up); >> - if (ret) { >> - if (!scale_up) >> - ufshcd_scale_gear(hba, true); >> - goto out; >> - } >> + if (ret) >> + goto scale_up_gear; >> >> /* scale up the gear after scaling up clocks */ >> if (scale_up) { >> ret = ufshcd_scale_gear(hba, true); >> if (ret) { >> ufshcd_scale_clks(hba, false); >> - goto out; >> + goto clk_scaling_unprepare; >> } >> } >> >> - ret = ufshcd_vops_clk_scale_notify(hba, scale_up, >> POST_CHANGE); >> + goto clk_scaling_unprepare; > I think you should find a way to make this function more readable. > Adding all those "spaghetti" gotos making it even harder to read. > > Thanks, > Avri >
This is just a collection of Subhash's changes. I think the 2 clk_scaling_unprepare and out gotos make sense, but the scale_up_gear goto is a bit vague. I will remove the scale_up_gear goto.
Thanks,
Can Guo.
>> >> -out: >> +scale_up_gear: >> + if (!scale_up) >> + ufshcd_scale_gear(hba, true); >> +clk_scaling_unprepare: >> ufshcd_clock_scaling_unprepare(hba); >> +out: >> ufshcd_release(hba); >> return ret; >> } >> @@ -6251,7 +6275,7 @@ static int ufshcd_host_reset_and_restore(struct >> ufs_hba *hba) >> spin_unlock_irqrestore(hba->host->host_lock, flags); >> >> /* scale up clocks to max frequency before full >> reinitialization */ >> - ufshcd_scale_clks(hba, true); >> + ufshcd_set_clk_freq(hba, true); >> >> err = ufshcd_hba_enable(hba); >> if (err) >> -- >> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a >> Linux Foundation Collaborative Project.
| |