Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757579AbaGAIGg (ORCPT ); Tue, 1 Jul 2014 04:06:36 -0400 Received: from hqemgate16.nvidia.com ([216.228.121.65]:17892 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757485AbaGAIGO (ORCPT ); Tue, 1 Jul 2014 04:06:14 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Tue, 01 Jul 2014 00:55:59 -0700 Message-ID: <53B26BF2.7090009@nvidia.com> Date: Tue, 1 Jul 2014 11:06:10 +0300 From: Mikko Perttunen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Stephen Warren , "rui.zhang@intel.com" , "edubezval@gmail.com" , "thierry.reding@gmail.com" , Peter De Schrijver , Matthew Longnecker CC: "linux-pm@vger.kernel.org" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH 6/6] thermal: Add Tegra SOCTHERM thermal management driver References: <1403856699-2140-1-git-send-email-mperttunen@nvidia.com> <1403856699-2140-7-git-send-email-mperttunen@nvidia.com> <53B1D538.6000704@wwwdotorg.org> In-Reply-To: <53B1D538.6000704@wwwdotorg.org> X-NVConfidentiality: public Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Inline. On 01/07/14 00:23, Stephen Warren wrote: > On 06/27/2014 02:11 AM, Mikko Perttunen wrote: >> This adds support for the Tegra SOCTHERM thermal sensing and management >> system found in the Tegra124 system-on-chip. This initial driver supports >> the four thermal zones with hardware-tracked trip points. > >> diff --git a/drivers/thermal/tegra_soctherm.c b/drivers/thermal/tegra_soctherm.c > >> +static struct tegra_tsensor t124_tsensors[] = { >> + { >> + .base = 0xc0, >> + .name = "cpu0", >> + .config = &t124_tsensor_config, >> + .calib_fuse_offset = 0x098, >> + .fuse_corr_alpha = 1135400, >> + .fuse_corr_beta = -6266900, >> + }, > > I wonder why some of those fields are named "fuse_xxx" when the values > are hard-coded in these tables rather than read from fuses? These values > don't seem to be used to adjust values read from fuses. They are used to when calculating the thermal calibration in calculate_tsensor_calibration, which is based on the value read from the fuse. Downstream calls them fuse correction values, so I kept that. (I guess the meaning of corr might not be obvious..) On downstream there is another set of these correction values used depending on the fuse revision, but I believe the older revision is only found internally. > >> +static int tegra_thermctl_get_temp(void *data, long *out_temp) > >> + switch (zone->sensor) { >> + case 0: >> + val = readl(zone->tegra->regs + SENSOR_TEMP1) >> + >> SENSOR_TEMP1_CPU_TEMP_SHIFT; > > Can't the register offset and shift be stored in *zone, so that this > whole switch can be replaced with something generic: > > val = readl(zone->tegra->regs + zone->reg_offset) >> zone->value_shift; Yes, certainly doable. > >> +static int tegra_soctherm_probe(struct platform_device *pdev) > >> + irq = platform_get_irq(pdev, 0); >> + if (irq <= 0) { >> + dev_err(&pdev->dev, "can't get interrupt\n"); >> + return -EINVAL; >> + } > > irq is assigned once here ... (see later) > >> + for (i = 0; i < 4; ++i) { > > Why "4"? Should the loop count be the ARRAY_SIZE(some array)? At the > very least, a named constant that describes the value would be useful... The thermctl sensors have been unchanged for a few chip generations, so I was thinking that just hardcoding this wouldn't be so bad. But I guess an array would look nicer here. Will fix. > >> + err = devm_request_threaded_irq(&pdev->dev, irq, soctherm_isr, >> + soctherm_isr_thread, >> + IRQF_SHARED, "tegra_soctherm", >> + zone); > > Why request the same IRQ 4 times here. Rather, shouldn't the IRQ be > requested once, and the ISR simply loop over the status register (or > whatever there are 4 of)? > I had that variant as well, but since we need to pass the list of tripped sensors to soctherm_isr_thread somehow, I guess some kind of locking or atomic is needed. This version doesn't need that, so I went with it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/