From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E4A0718BC3D for ; Tue, 2 Dec 2025 02:33:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764642797; cv=none; b=IkJZtELxNjH0GBm7pYK+obM6tI1t4yHmYaBTt50wyxgVpg/IAPrEBDJfQfj35uQQlbAI0yUgaI3KQB3NN/kY4K6kZhWijNCV4gIpitNwIFHeFBdcRAO2cdKJDjMSMrDsprbcpaTHmhuSRGupJYHwo6iGNoi6pTE778i4bKHZe4U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764642797; c=relaxed/simple; bh=RsMwrNy8Wm0cl7fZsRJnAu1DykqfOliIPjIpOjh1RN0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DJIS0hdZJ89KwM8ry63YSIf17s/dwB/AtZtegdzgiBCADj7JM7bD9bvhwSWqxztxsie1gS2YocHQcVVzM6VAXv4OUFcGkAYckdPU2DcmmBbFjRyGZOj098EK4c4YWeZtrPKuTzJuNvGsQ5KWQtmZlRBRSiFZISgKPORW4GyT0k0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZmLyLWW0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZmLyLWW0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5A7AC4CEF1; Tue, 2 Dec 2025 02:33:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764642796; bh=RsMwrNy8Wm0cl7fZsRJnAu1DykqfOliIPjIpOjh1RN0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ZmLyLWW0LxhBBTSmvj4/LaiO+gTdPKqptIayOsa+QpPN6gfcEGeiz7oLQXgJ4iZhb lI1OQV89fKAvcTPQDhFoT2DIEsfU9pkfUdaeo62TtTcff5ui1QnPaj08XaK309bNQ6 T53jsTDxur2Jn1uLhy5UVFDzYSHCuCAdDJBwfGlipFXiubpKOKVx7ybNJG8Wi2K/2W 73gMQg2wYjgOXquLVD+ggzwcPp/B0hvb2b8RQUgz7wQV6MeFUvv3zPJuT4OsGTSOdF hZ3c3WrjAXXQQHeJgd1K8Dzr8LSJT5G36D0Z2qinqw/9Iuaqq4Wlkn1yImxafonlpK zwwtgcfjlahZA== Message-ID: <4d6063d0-5810-4449-a00d-bc397c2ead91@kernel.org> Date: Tue, 2 Dec 2025 11:33:14 +0900 Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 6/8] ata: libata: Add support to parse equal sign in libata.force To: Niklas Cassel Cc: linux-ide@vger.kernel.org, xxjack12xx@gmail.com, "Martin K. Petersen" References: <20251201123501.246282-10-cassel@kernel.org> <20251201123501.246282-16-cassel@kernel.org> Content-Language: en-US From: Damien Le Moal Organization: Western Digital Research In-Reply-To: <20251201123501.246282-16-cassel@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/1/25 21:35, Niklas Cassel wrote: > Currently, no libata.force parameter supports an arbitrary value. > > All allowed values, e.g. udma/16, udma/25, udma/33, udma/44, udma/66, > udma/100, udma/133 have hardcoded entries in the force_tbl table. > > Add code to allow a libata.force param with the format > libata.force=param=param_value, where param_value can be an arbitrary > value. > > This code will be used in a follow up commit. > > Signed-off-by: Niklas Cassel > Reviewed-by: Martin K. Petersen A couple of nits below. Reviewed-by: Damien Le Moal > --- > drivers/ata/libata-core.c | 38 ++++++++++++++++++++++++++++++++++++-- > 1 file changed, 36 insertions(+), 2 deletions(-) > > diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c > index 697188b990dd6..7f59eca2a65be 100644 > --- a/drivers/ata/libata-core.c > +++ b/drivers/ata/libata-core.c > @@ -6461,6 +6461,13 @@ EXPORT_SYMBOL_GPL(ata_platform_remove_one); > { "no" #name, .quirk_on = (flag) }, \ > { #name, .quirk_off = (flag) } > > +/* > + * If the ata_force_param struct member 'name' ends with '=', then the value > + * after the equal sign will be parsed as an u64, and will be saved in the > + * ata_force_param struct member 'value'. This works because each libata.force > + * entry (struct ata_force_ent) is separated by commas, so each entry represents > + * a single quirk, and can thus only have a single value. s/have/has > + */ > static const struct ata_force_param force_tbl[] __initconst = { > force_cbl(40c, ATA_CBL_PATA40), > force_cbl(80c, ATA_CBL_PATA80), > @@ -6548,8 +6555,9 @@ static int __init ata_parse_force_one(char **cur, > const char **reason) > { > char *start = *cur, *p = *cur; > - char *id, *val, *endp; > + char *id, *val, *endp, *equalsign, *char_after_equalsign; > const struct ata_force_param *match_fp = NULL; > + u64 val_after_equalsign; > int nr_matches = 0, i; > > /* find where this param ends and update *cur */ > @@ -6592,10 +6600,36 @@ static int __init ata_parse_force_one(char **cur, > } > > parse_val: > - /* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */ > + equalsign = strchr(val, '='); > + if (equalsign) { > + char_after_equalsign = equalsign + 1; > + if (!strlen(char_after_equalsign) || > + kstrtoull(char_after_equalsign, 10, &val_after_equalsign)) { > + *reason = "invalid value after equal sign"; > + return -EINVAL; > + } > + } > + > + /* parse val */ /* Parse the parameter value. */ > for (i = 0; i < ARRAY_SIZE(force_tbl); i++) { > const struct ata_force_param *fp = &force_tbl[i]; > > + /* > + * If val contains equal sign, match has to be exact, i.e. > + * shortcuts are not supported. > + */ > + if (equalsign && > + (strncasecmp(val, fp->name, > + char_after_equalsign - val) == 0)) { > + force_ent->param = *fp; > + force_ent->param.value = val_after_equalsign; > + return 0; > + } > + > + /* > + * If val does not contain equal sign, allow shortcuts so that > + * both 1.5 and 1.5Gbps work. > + */ > if (strncasecmp(val, fp->name, strlen(val))) > continue; > -- Damien Le Moal Western Digital Research