From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Cf0r6khS" Received: from mail-qk1-x72c.google.com (mail-qk1-x72c.google.com [IPv6:2607:f8b0:4864:20::72c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C20E8C4 for ; Mon, 20 Nov 2023 14:46:09 -0800 (PST) Received: by mail-qk1-x72c.google.com with SMTP id af79cd13be357-778a92c06d6so312708985a.2 for ; Mon, 20 Nov 2023 14:46:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1700520369; x=1701125169; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=njoGUAO/aKU6y+B0kYXrWx9rr0gLschtaZIB6sJvVdU=; b=Cf0r6khSUB9nvaHf3+ily/2Rp8cWMG0TRIv6aMoSEBXFCdaSl8WzpWnoUsvv0Lv8h8 NpVUd1YnZ0HDpnXRKVLLeh/IPV2/IJLJNoucia/xr9s0nb/Dg6BW6wrK1i0T3zKJ2Bmq t1ooAhxtjKC5kwQyUayLVY1CoIL3Lt06p2NaX16HCfd+cGX32BFqEUcH8PNab/pRGaaM jbVi/RBIhpMhN3gTKWbOX+YhHmVVs7EjGEI0zUpaKhtnk+PuOFH+Vq+Bo9hQtal5rHme GaG5Qh2NcDlp1P9RtKSYA9pIPIs2tubVY6O01ZytGMSGYYLWKY86NtFaodeWfi2El788 ToXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700520369; x=1701125169; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=njoGUAO/aKU6y+B0kYXrWx9rr0gLschtaZIB6sJvVdU=; b=itmXBlOYgpDihGRbbSsYzChTkdJLc8MSZy2oOTBS+KsM/KbekmFYEat9rsyt/9VYlU Lgmf9Rj3Tq9KDl7jEv/luSCIBw5nBSfkQ0MmBGXI0U4IoeUIfs84BWjV0mdKLVDCCzTX k6kGpfGz4pXmSoKmh+DoZdId+BCj1BxSPbIMrzNDacEuoL4+m6vP3/b8r/U0t+hlSTyB 2MvQvXfujMD2nS856rQwRoR6Z95khknXItmCBB5NgEhmpp3qTPNv4wXtFMDuKlvyuu8/ HXE6BIAV8JDXt3c6FBVT6URezGiYCxVLqLumZW2MrPDV3QoAud+1lmDLEdk9qPU3WoOv o9Iw== X-Gm-Message-State: AOJu0YwuZQzAEtOCiUVKQWt5l83jRpSVdqwzwyZKCvMlUkTWp9Gv2OSC Jb5T34VTquCgqjrsx60dZZdCxo277+y6lDP9XnmxBg== X-Google-Smtp-Source: AGHT+IG/+m3xt7ccY8eDIleAiRsOAh79Ehhifx5D3WhBv4fQmrHh9AAauod19bUGyqw4eilwyZq13diIFEILCwXsTac= X-Received: by 2002:ad4:4ea9:0:b0:679:e195:b071 with SMTP id ed9-20020ad44ea9000000b00679e195b071mr3321524qvb.9.1700520368792; Mon, 20 Nov 2023 14:46:08 -0800 (PST) Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20231120212037.911774-1-peter.griffin@linaro.org> <20231120212037.911774-16-peter.griffin@linaro.org> <5ee955e4-4c22-4696-8001-1e4f24952eeb@roeck-us.net> In-Reply-To: <5ee955e4-4c22-4696-8001-1e4f24952eeb@roeck-us.net> From: Peter Griffin Date: Mon, 20 Nov 2023 22:45:57 +0000 Message-ID: Subject: Re: [PATCH v4 15/19] watchdog: s3c2410_wdt: Add support for WTCON register DBGACK_MASK bit To: Guenter Roeck Cc: robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, mturquette@baylibre.com, conor+dt@kernel.org, sboyd@kernel.org, tomasz.figa@gmail.com, s.nawrocki@samsung.com, linus.walleij@linaro.org, wim@linux-watchdog.org, catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, olof@lixom.net, gregkh@linuxfoundation.org, jirislaby@kernel.org, cw00.choi@samsung.com, alim.akhtar@samsung.com, tudor.ambarus@linaro.org, andre.draszik@linaro.org, semen.protsenko@linaro.org, saravanak@google.com, willmcvicker@google.com, soc@kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, linux-watchdog@vger.kernel.org, kernel-team@android.com, linux-serial@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Hi Guenter, Thanks for the review. On Mon, 20 Nov 2023 at 22:00, Guenter Roeck wrote: > > On 11/20/23 13:20, Peter Griffin wrote: > > The WDT uses the CPU core signal DBGACK to determine whether the SoC > > is running in debug mode or not. If the DBGACK signal is asserted and > > DBGACK_MASK is enabled, then WDT output and interrupt is masked. > > > > Presence of the DBGACK_MASK bit is determined by adding a new > > QUIRK_HAS_DBGACK_BIT quirk. Currently only gs101 SoC is known to have > > the DBGACK_MASK bit so add the quirk to drv_data_gs101_cl1 and > > drv_data_gs101_cl1 quirks. > > > > Signed-off-by: Peter Griffin > > --- > > drivers/watchdog/s3c2410_wdt.c | 32 +++++++++++++++++++++++++++----- > > 1 file changed, 27 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c > > index 08b8c57dd812..ed561deeeed9 100644 > > --- a/drivers/watchdog/s3c2410_wdt.c > > +++ b/drivers/watchdog/s3c2410_wdt.c > > @@ -34,9 +34,10 @@ > > > > #define S3C2410_WTCNT_MAXCNT 0xffff > > > > -#define S3C2410_WTCON_RSTEN (1 << 0) > > -#define S3C2410_WTCON_INTEN (1 << 2) > > -#define S3C2410_WTCON_ENABLE (1 << 5) > > +#define S3C2410_WTCON_RSTEN (1 << 0) > > +#define S3C2410_WTCON_INTEN (1 << 2) > > +#define S3C2410_WTCON_ENABLE (1 << 5) > > +#define S3C2410_WTCON_DBGACK_MASK (1 << 16) > > > > #define S3C2410_WTCON_DIV16 (0 << 3) > > #define S3C2410_WTCON_DIV32 (1 << 3) > > @@ -107,12 +108,16 @@ > > * %QUIRK_HAS_PMU_CNT_EN: PMU block has some register (e.g. CLUSTERx_NONCPU_OUT) > > * with "watchdog counter enable" bit. That bit should be set to make watchdog > > * counter running. > > + * > > + * %QUIRK_HAS_DBGACK_BIT: WTCON register has DBGACK_MASK bit. Enables masking > > + * WDT interrupt and reset request according to CPU core DBGACK signal. > > This is a bit difficult to understand. I _think_ it means that the DBGACK_MASK bit > has to be set to be able to trigger interrupt and reset requests. Not quite, it is a bit that controls masking the watchdog outputs when the SoC is in debug mode. > "masking" normally refers to disabling something (at least in interrupt context). > "Enables masking WDT interrupt" sounds like the bit has to be set in order to > be able to disable interupts, and the code below suggests that the bit has to be > set for the driver to work. Is that the case ? It might make sense to explain this > a bit further. Maybe I explained it more clearly in the commit message than the comment "The WDT uses the CPU core signal DBGACK to determine whether the SoC is running in debug mode or not. If the DBGACK signal is asserted and DBGACK_MASK is enabled, then WDT output and interrupt is masked." Is that any clearer? Or maybe simpler again "Enabling DBGACK_MASK bit masks the watchdog outputs when the SoC is in debug mode. Debug mode is determined by the DBGACK CPU signal." Let me know what you think is the clearest and most succinct and I can update the comment. > > > */ > > #define QUIRK_HAS_WTCLRINT_REG (1 << 0) > > #define QUIRK_HAS_PMU_MASK_RESET (1 << 1) > > #define QUIRK_HAS_PMU_RST_STAT (1 << 2) > > #define QUIRK_HAS_PMU_AUTO_DISABLE (1 << 3) > > #define QUIRK_HAS_PMU_CNT_EN (1 << 4) > > +#define QUIRK_HAS_DBGACK_BIT (1 << 5) > > > > /* These quirks require that we have a PMU register map */ > > #define QUIRKS_HAVE_PMUREG \ > > @@ -279,7 +284,7 @@ static const struct s3c2410_wdt_variant drv_data_gs101_cl0 = { > > .cnt_en_reg = GS_CLUSTER0_NONCPU_OUT, > > .cnt_en_bit = 8, > > .quirks = QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_CNT_EN | > > - QUIRK_HAS_WTCLRINT_REG, > > + QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_DBGACK_BIT, > > }; > > > > static const struct s3c2410_wdt_variant drv_data_gs101_cl1 = { > > @@ -291,7 +296,7 @@ static const struct s3c2410_wdt_variant drv_data_gs101_cl1 = { > > .cnt_en_reg = GS_CLUSTER1_NONCPU_OUT, > > .cnt_en_bit = 7, > > .quirks = QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_CNT_EN | > > - QUIRK_HAS_WTCLRINT_REG, > > + QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_DBGACK_BIT, > > }; > > > > static const struct of_device_id s3c2410_wdt_match[] = { > > @@ -408,6 +413,21 @@ static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en) > > return 0; > > } > > > > +static void s3c2410wdt_mask_dbgack(struct s3c2410_wdt *wdt, bool mask) > > I think I must be missing something. This is only ever called with mask==true, > meaning the bit, if present, is always set. > > Why not call the function s3c2410wdt_set_dbgack() and drop the unnecessary > parameter ? I can update like you suggest, it would simplify the logic a little bit. regards, Peter.