From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rajendra Nayak <rnayak@codeaurora.org>
Cc: sboyd@kernel.org, bjorn.andersson@linaro.org, agross@kernel.org,
linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 01/21] opp: Manage empty OPP tables with clk handle
Date: Thu, 9 Apr 2020 13:27:24 +0530 [thread overview]
Message-ID: <20200409075724.7t3bt3oxaxoygldb@vireshk-i7> (raw)
In-Reply-To: <1586353607-32222-2-git-send-email-rnayak@codeaurora.org>
On 08-04-20, 19:16, Rajendra Nayak wrote:
> With OPP core now supporting DVFS for IO devices, we have instances of
> IO devices (same IP block) which require an OPP on some platforms/SoCs
By OPP you mean both freq and voltage here ?
> while just needing to scale the clock on some others.
And only freq here ?
> In order to avoid conditional code in every driver which supports such
> devices (to check for availability of OPPs and then deciding to do
> either dev_pm_opp_set_rate() or clk_set_rate()) add support to manage
> empty OPP tables with a clk handle.
Why can't these devices have an opp table with just rate mentioned in each node
?
> This makes dev_pm_opp_set_rate() equivalent of a clk_set_rate() for
> devices with just a clk and no OPPs specified, and makes
> dev_pm_opp_set_rate(0) bail out without throwing an error.
>
> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
> ---
> drivers/opp/core.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index ba43e6a..e4f01e7 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -819,6 +819,8 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
> if (unlikely(!target_freq)) {
> if (opp_table->required_opp_tables) {
> ret = _set_required_opps(dev, opp_table, NULL);
> + } else if (!_get_opp_count(opp_table)) {
> + return 0;
Why should anyone call this with target_freq = 0 ? I know it was required to
drop votes in the above case, but why here ?
> } else {
> dev_err(dev, "target frequency can't be 0\n");
> ret = -EINVAL;
> @@ -849,6 +851,18 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
> goto put_opp_table;
> }
>
> + /*
> + * For IO devices which require an OPP on some platforms/SoCs
> + * while just needing to scale the clock on some others
> + * we look for empty OPP tables with just a clock handle and
> + * scale only the clk. This makes dev_pm_opp_set_rate()
> + * equivalent to a clk_set_rate()
> + */
> + if (!_get_opp_count(opp_table)) {
> + ret = _generic_set_opp_clk_only(dev, clk, freq);
> + goto put_opp_table;
> + }
> +
Is this enough? _of_add_opp_table_v2() returns with error if there is no OPP
node within the table. Please give an example of how DT looks for the case you
want to support.
> temp_freq = old_freq;
> old_opp = _find_freq_ceil(opp_table, &temp_freq);
> if (IS_ERR(old_opp)) {
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
--
viresh
next prev parent reply other threads:[~2020-04-09 8:04 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-08 13:46 [PATCH 00/21] DVFS for IO devices on sdm845 and sc7180 Rajendra Nayak
2020-04-08 13:46 ` [PATCH 01/21] opp: Manage empty OPP tables with clk handle Rajendra Nayak
2020-04-09 7:57 ` Viresh Kumar [this message]
2020-04-13 10:34 ` Rajendra Nayak
2020-04-13 10:42 ` Viresh Kumar
2020-04-14 6:57 ` Viresh Kumar
2020-04-08 13:46 ` [PATCH 02/21] tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state Rajendra Nayak
2020-04-09 17:45 ` Matthias Kaehlcke
2020-04-10 8:36 ` Jun Nie
2020-04-13 14:22 ` Rajendra Nayak
2020-04-14 5:26 ` Jun Nie
2020-04-13 13:58 ` Rajendra Nayak
2020-04-10 6:56 ` Akash Asthana
2020-04-10 12:52 ` Akash Asthana
2020-04-13 14:13 ` Rajendra Nayak
2020-04-08 13:46 ` [PATCH 03/21] spi: spi-geni-qcom: " Rajendra Nayak
2020-04-09 18:20 ` Matthias Kaehlcke
2020-04-13 14:02 ` Rajendra Nayak
2020-04-08 13:46 ` [PATCH 04/21] arm64: dts: sdm845: Add OPP table for all qup devices Rajendra Nayak
2020-04-08 13:46 ` [PATCH 05/21] arm64: dts: sc7180: " Rajendra Nayak
2020-04-08 13:46 ` [PATCH 06/21] scsi: ufs: Add support to manage multiple power domains in ufshcd-pltfrm Rajendra Nayak
2020-04-08 13:46 ` [PATCH 07/21] scsi: ufs: Add support for specifying OPP tables in DT Rajendra Nayak
2020-04-08 13:46 ` [PATCH 08/21] arm64: dts: sdm845: Add ufs opps and power-domains Rajendra Nayak
2020-04-08 13:46 ` [PATCH 09/21] drm/msm/dpu: Use OPP API to set clk/perf state Rajendra Nayak
2020-04-08 13:46 ` [PATCH 10/21] drm/msm: dsi: " Rajendra Nayak
2020-04-08 13:46 ` [PATCH 11/21] arm64: dts: sdm845: Add DSI and MDP OPP tables and power-domains Rajendra Nayak
2020-04-08 13:46 ` [PATCH 12/21] arm64: dts: sc7180: " Rajendra Nayak
2020-04-08 13:46 ` [PATCH 13/21] mmc: sdhci-msm: Use OPP API to set clk/perf state Rajendra Nayak
2020-04-15 13:52 ` Ulf Hansson
2020-04-15 16:43 ` Rajendra Nayak
2020-04-16 3:39 ` Viresh Kumar
2020-04-16 8:21 ` Ulf Hansson
2020-04-16 8:23 ` Ulf Hansson
2020-04-08 13:46 ` [PATCH 14/21] arm64: dts: sdm845: Add sdhc opps and power-domains Rajendra Nayak
2020-04-08 13:46 ` [PATCH 15/21] arm64: dts: sc7180: " Rajendra Nayak
2020-04-08 13:46 ` [PATCH 16/21] media: venus: core: Add support for opp tables/perf voting Rajendra Nayak
2020-04-08 13:46 ` [PATCH 17/21] arm64: dts: sdm845: Add OPP tables and power-domains for venus Rajendra Nayak
2020-04-08 13:46 ` [PATCH 18/21] arm64: dts: sc7180: " Rajendra Nayak
2020-04-08 13:46 ` [PATCH 19/21] spi: spi-qcom-qspi: Use OPP API to set clk/perf state Rajendra Nayak
2020-04-08 13:46 ` [PATCH 20/21] arm64: dts: sdm845: Add qspi opps and power-domains Rajendra Nayak
2020-04-08 13:46 ` [PATCH 21/21] arm64: dts: sc7180: " Rajendra Nayak
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