From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH v16 00/11] Convert PWM period and duty cycle to u64 Date: Thu, 11 Jun 2020 20:24:30 +0200 Message-ID: <20200611182430.GA2293927@ulmo> References: <20200611165505.GA9335@codeaurora.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="2oS5YaxWCcQjTEyO" Return-path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726386AbgFKSYg (ORCPT ); Thu, 11 Jun 2020 14:24:36 -0400 Content-Disposition: inline In-Reply-To: <20200611165505.GA9335@codeaurora.org> Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Guru Das Srinagesh Cc: linux-pwm@vger.kernel.org, Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , Subbaraman Narayanamurthy , David Collins , linux-kernel@vger.kernel.org, Joe Perches , Stephen Boyd , Lee Jones , Arnd Bergmann , Geert Uytterhoeven , Guenter Roeck , Daniel Thompson , Dan Carpenter , linux-arm-kernel@lists.infradead.org --2oS5YaxWCcQjTEyO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 11, 2020 at 09:55:05AM -0700, Guru Das Srinagesh wrote: > On Tue, Jun 02, 2020 at 03:31:04PM -0700, Guru Das Srinagesh wrote: > > Because period and duty cycle are defined in the PWM framework structs = as ints > > with units of nanoseconds, the maximum time duration that can be set is= limited > > to ~2.147 seconds. Consequently, applications desiring to set greater t= ime > > periods via the PWM framework are not be able to do so - like, for inst= ance, > > causing an LED to blink at an interval of 5 seconds. > >=20 > > Redefining the period and duty cycle struct members in the core PWM fra= mework > > structs as u64 values will enable larger time durations to be set and s= olve > > this problem. Such a change to the framework mandates that drivers usin= g these > > struct members (and corresponding helper functions) also be modified co= rrectly > > in order to prevent compilation errors. > >=20 > > This patch series introduces the changes to all the drivers first, foll= owed by > > the framework change at the very end so that when the latter is applied= , all > > the drivers are in good shape and there are no compilation errors. > >=20 > > Changes from v15: > > - Rebased to tip of for-next. > >=20 > > Changes from v14: > > - Collected Uwe's Acked-by for the pwm core patch. > > - Addressed comments in pwm-clps711x.c. > >=20 > > Changes from v13: > > - Pruned cc-list and added same (reduced) set of reviewers to all pat= ches. > > - Added Lee Jones' Acked-by to the pwm_bl.c patch. > > - Added Jani Nikula's Acked-by to intel-panel.c patch. > > - Added Stephen Boyd's Acked-by to pwm-clk.c patch. > > - Addressed Geert's review comments in clps711x.c patch. > >=20 > > Changes from v12: > > - Rebased to tip of for-next > > - Collected Acked-by for sun4i > > - Reworked patch for intel-panel.c due to rebase, dropped Jani's Acke= d-by as > > a result > >=20 > > Changes from v11: > > - Rebased to tip of for-next. > > - Collected "Acked-by:" for v7 (unchanged) of pwm: sifive: [4] > > - Squished stm32-lp.c change with final patch in series > > - sun4i: Used nsecs_to_jiffies() > > - imx27: Added overflow handling logic > > - clps711x: Corrected the if condition for skipping the division > > - clk: pwm: Reverted to v8 version, added check to prevent division-b= y-zero > >=20 > > Changes from v10: > > - Carefully added back all the "Reviewed-by: " and "Acked-by: " tags = received > > so far that had gotten missed in v9. No other changes. > >=20 > > Changes from v9: > > - Gathered the received "Reviewed-by: " tag > > - Added back the clk-pwm.c patch because kbuild test robot complained= [3] > > and addressed received review comments. > > - clps711x: Addressed review comments. > >=20 > > Changes from v8: > > - Gathered all received "Acked-by: " and "Reviewed-by: " tags > > - Dropped patch to clk-pwm.c for reasons mentiond in [2] > > - Expanded audience of unreviewed patches > >=20 > > Changes from v7: > > - Changed commit messages of all patches to be brief and to the point. > > - Added explanation of change in cover letter. > > - Dropped change to pwm-sti.c as upon review it was unnecessary as st= ruct > > pwm_capture is not being modified in the PWM core. > >=20 > > Changes from v6: > > - Split out the driver changes out into separate patches, one patch p= er file > > for ease of reviewing. > >=20 > > Changes from v5: > > - Dropped the conversion of struct pwm_capture to u64 for reasons men= tioned > > in https://www.spinics.net/lists/linux-pwm/msg11541.html > >=20 > > Changes from v4: > > - Split the patch into two: one for changes to the drivers, and the a= ctual > > switch to u64 for ease of reverting should the need arise. > > - Re-examined the patch and made the following corrections: > > * intel_panel.c: > > DIV64_U64_ROUND_UP -> DIV_ROUND_UP_ULL (as only the numerator would be > > 64-bit in this case). > > * pwm-sti.c: > > do_div -> div_u64 (do_div is optimized only for x86 architectures, and > > div_u64's comment block suggests to use this as much as possible). > >=20 > > Changes from v3: > > - Rebased to current tip of for-next. > >=20 > > Changes from v2: > > - Fixed %u -> %llu in a dev_dbg in pwm-stm32-lp.c, thanks to kbuild t= est robot > > - Added a couple of fixes to pwm-imx-tpm.c and pwm-sifive.c > >=20 > > Changes from v1: > > - Fixed compilation errors seen when compiling for different archs. > >=20 > > v1: > > - Reworked the change pushed upstream earlier [1] so as to not add an > > extension to an obsolete API. With this change, pwm_ops->apply() ca= n be > > used to set pwm_state parameters as usual. > >=20 > > [1] https://lore.kernel.org/lkml/20190916140048.GB7488@ulmo/ > > [2] https://lore.kernel.org/lkml/20200312190859.GA19605@xxxxxxxxxxxxxx/ > > [3] https://www.spinics.net/lists/linux-pwm/msg11906.html > > [4] https://www.spinics.net/lists/linux-pwm/msg11986.html > >=20 > > Guru Das Srinagesh (11): > > drm/i915: Use 64-bit division macro > > hwmon: pwm-fan: Use 64-bit division macro > > ir-rx51: Use 64-bit division macro > > pwm: clps711x: Use 64-bit division macro > > pwm: pwm-imx-tpm: Use 64-bit division macro > > pwm: imx27: Use 64-bit division macro and function > > pwm: sifive: Use 64-bit division macro > > pwm: sun4i: Use nsecs_to_jiffies to avoid a division > > backlight: pwm_bl: Use 64-bit division function > > clk: pwm: Use 64-bit division function > > pwm: core: Convert period and duty cycle to u64 > >=20 > > drivers/clk/clk-pwm.c | 7 ++++- > > drivers/gpu/drm/i915/display/intel_panel.c | 2 +- > > drivers/hwmon/pwm-fan.c | 2 +- > > drivers/media/rc/ir-rx51.c | 3 +- > > drivers/pwm/core.c | 14 ++++----- > > drivers/pwm/pwm-clps711x.c | 2 +- > > drivers/pwm/pwm-imx-tpm.c | 2 +- > > drivers/pwm/pwm-imx27.c | 48 ++++++++++++++++++++++= ++++---- > > drivers/pwm/pwm-sifive.c | 2 +- > > drivers/pwm/pwm-stm32-lp.c | 2 +- > > drivers/pwm/pwm-sun4i.c | 2 +- > > drivers/pwm/sysfs.c | 8 ++--- > > drivers/video/backlight/pwm_bl.c | 3 +- > > include/linux/pwm.h | 12 ++++---- > > 14 files changed, 77 insertions(+), 32 deletions(-) > >=20 > > --=20 >=20 > Hello Thierry, Uwe, Lee, >=20 > Gentle reminder for this patch series :) Earlier discussions on next > steps were as per [1] and [2]. Hi Guru, I ended up deciding against queueing this for v5.8-rc1 because I want this to soak for a bit in linux-next. I'll apply them early next week after v5.8-rc1 is out. 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