From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753990AbdBHKis (ORCPT ); Wed, 8 Feb 2017 05:38:48 -0500 Received: from mail-wr0-f182.google.com ([209.85.128.182]:35365 "EHLO mail-wr0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752739AbdBHKi0 (ORCPT ); Wed, 8 Feb 2017 05:38:26 -0500 Date: Wed, 8 Feb 2017 10:04:58 +0000 From: Lee Jones To: Charles Keepax Cc: linux-kernel@vger.kernel.org, patches@opensource.wolfsonmicro.com Subject: Re: [PATCH RESEND 3/4] mfd: arizona: Update arizona_poll_reg to take a timeout in milliseconds Message-ID: <20170208100458.2nguskvyo2rlvft7@dell> References: <1485873843-8491-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> <1485873843-8491-3-git-send-email-ckeepax@opensource.wolfsonmicro.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1485873843-8491-3-git-send-email-ckeepax@opensource.wolfsonmicro.com> User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 31 Jan 2017, Charles Keepax wrote: > Currently, we specify the timeout in terms of the number of polls but it > is more clear from a user of the functions perspective to specify the > timeout directly in milliseconds, as such update the function to these new > semantics. > > Signed-off-by: Charles Keepax > --- > drivers/mfd/arizona-core.c | 17 +++++++++++------ > 1 file changed, 11 insertions(+), 6 deletions(-) > > diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c > index 4cb34c3..ae4cdc4 100644 > --- a/drivers/mfd/arizona-core.c > +++ b/drivers/mfd/arizona-core.c > @@ -235,14 +235,18 @@ static irqreturn_t arizona_overclocked(int irq, void *data) > return IRQ_HANDLED; > } > > +#define ARIZONA_REG_POLL_DELAY_MS 5 > + > static int arizona_poll_reg(struct arizona *arizona, > - int timeout, unsigned int reg, > + int timeout_ms, unsigned int reg, > unsigned int mask, unsigned int target) > { > + unsigned int npolls = (timeout_ms + ARIZONA_REG_POLL_DELAY_MS - 1) / > + ARIZONA_REG_POLL_DELAY_MS; Why the over-complication? Shouldn't this just be "timeout_ms / ARIZONA_REG_POLL_DELAY_MS"? > unsigned int val = 0; > int ret, i; > > - for (i = 0; i < timeout; i++) { > + for (i = 0; i < npolls; i++) { > ret = regmap_read(arizona->regmap, reg, &val); > if (ret != 0) { > dev_err(arizona->dev, "Failed to read reg 0x%x: %d\n", > @@ -253,7 +257,8 @@ static int arizona_poll_reg(struct arizona *arizona, > if ((val & mask) == target) > return 0; > > - usleep_range(1000, 5000); > + usleep_range((ARIZONA_REG_POLL_DELAY_MS * 1000) / 2, > + ARIZONA_REG_POLL_DELAY_MS * 1000); I'm sure there is a macro for conversion from ms to us. By using such a wide range, you are now not honouring the timeout set by the caller by as much as 50%. > } > > dev_err(arizona->dev, "Polling reg 0x%x timed out: %x\n", reg, val); > @@ -269,7 +274,7 @@ static int arizona_wait_for_boot(struct arizona *arizona) > * we won't race with the interrupt handler as it'll be blocked on > * runtime resume. > */ > - ret = arizona_poll_reg(arizona, 5, ARIZONA_INTERRUPT_RAW_STATUS_5, > + ret = arizona_poll_reg(arizona, 25, ARIZONA_INTERRUPT_RAW_STATUS_5, > ARIZONA_BOOT_DONE_STS, ARIZONA_BOOT_DONE_STS); > > if (!ret) > @@ -339,7 +344,7 @@ static int arizona_enable_freerun_sysclk(struct arizona *arizona, > ret); > return ret; > } > - ret = arizona_poll_reg(arizona, 25, ARIZONA_INTERRUPT_RAW_STATUS_5, > + ret = arizona_poll_reg(arizona, 125, ARIZONA_INTERRUPT_RAW_STATUS_5, > ARIZONA_FLL1_CLOCK_OK_STS, > ARIZONA_FLL1_CLOCK_OK_STS); > if (ret) > @@ -403,7 +408,7 @@ static int wm5102_apply_hardware_patch(struct arizona *arizona) > goto err; > } > > - ret = arizona_poll_reg(arizona, 5, ARIZONA_WRITE_SEQUENCER_CTRL_1, > + ret = arizona_poll_reg(arizona, 25, ARIZONA_WRITE_SEQUENCER_CTRL_1, > ARIZONA_WSEQ_BUSY, 0); > if (ret) > regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0, -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog