On 3/25/2020 6:11 AM, Avri Altman wrote:
Currently, the frequency that devfreq provides the driver to set always leads the clocks to be scaled up. Hence, round the clock-rate to the nearest frequency before deciding to scale. Also update the devfreq statistics of current frequency. Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 2a2a63b..4607bc6 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1187,6 +1187,9 @@ static int ufshcd_devfreq_target(struct device *dev, if (!ufshcd_is_clkscaling_supported(hba)) return -EINVAL; + clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info, list); + /* Override with the closest supported frequency */ + *freq = (unsigned long) clk_round_rate(clki->clk, *freq); spin_lock_irqsave(hba->host->host_lock, irq_flags);Please remind me what the spin lock is protecting here?
Hmmm ... Nothing comes to my mind. I blamed it but it's a part of a bigger change.
if (ufshcd_eh_in_progress(hba)) { spin_unlock_irqrestore(hba->host->host_lock, irq_flags); @@ -1201,8 +1204,13 @@ static int ufshcd_devfreq_target(struct device *dev, goto out; } - clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info, list); + /* Decide based on the rounded-off frequency and update */ scale_up = (*freq == clki->max_freq) ? true : false; + if (scale_up) + *freq = clki->max_freq;This was already established 2 lines above ?
Good point - I'll change it.
Sure - I'll add a comment. If stat->current_frequency is not updated, the governor would always ask to set the max freq because the initial frequency was unknown to it. Reference - devfreq_simple_ondemand_func(...)+ else + *freq = clki->min_freq; + /* Update the frequency */ if (!ufshcd_is_devfreq_scaling_required(hba, scale_up)) { spin_unlock_irqrestore(hba->host->host_lock, irq_flags); ret = 0; @@ -1250,6 +1258,8 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev, struct ufs_hba *hba = dev_get_drvdata(dev); struct ufs_clk_scaling *scaling = &hba->clk_scaling; unsigned long flags; + struct list_head *clk_list = &hba->clk_list_head; + struct ufs_clk_info *clki; if (!ufshcd_is_clkscaling_supported(hba)) return -EINVAL; @@ -1260,6 +1270,8 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev, if (!scaling->window_start_t) goto start_window; + clki = list_first_entry(clk_list, struct ufs_clk_info, list); + stat->current_frequency = clki->curr_freq;Is this a bug fix? > devfreq_simple_ondemand_func is trying to establish the busy period, but also uses the frequency in its calculation - which I wasn't able to understand how. Can you add a short comment why updating current_frequency is needed?
Thanks, Avri
Thanks, -asd -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, Linux Foundation Collaborative Project
