From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF67DC4167B for ; Sat, 2 Dec 2023 12:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232576AbjLBMBo (ORCPT ); Sat, 2 Dec 2023 07:01:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229472AbjLBMBn (ORCPT ); Sat, 2 Dec 2023 07:01:43 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87CFA123 for ; Sat, 2 Dec 2023 04:01:49 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFB60C433C9; Sat, 2 Dec 2023 12:01:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701518509; bh=qGF18cj5rouLI1EH0KmHGn52Fmi+W0AJNsfWPtuN2qw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Ra4lMt8xEm7aZSkJnkPN72ti44Ti5DIfsTJQqmyjLy907PoxtAFpV9zCl1c9jaJOA 8tUJo3wxPJj15A2X0GDshgVaaOIH2bOS4ZQ938qq5/EqOZ1nd4zX9p70DkG2MRJo/L uYJGbssiqgMv8xXFGm+UAMobvSl6HtCmZRKxa5gksqp0uskezGm/ubvcWmnv+mV328 PPCOrSYgAvfu8unQhiSh3Bb/GmjHgvSh3LY1zAQwQe4vWeRfHKtkXbNl4VhCrsACK3 fd3/T0hF85mOdPj2TichFRJy98nrxntBDoh1wHzlB1ralt5jN8KhLj+1s/gPKWNsVd 8NhpTj7c+iKsw== Message-ID: <5ccc0a13-01e1-464c-980b-bdf34970cc33@kernel.org> Date: Sat, 2 Dec 2023 13:01:42 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/5] w1: ds2490: support block sizes larger than 128 bytes in ds_read_block To: marc.ferland@gmail.com, krzysztof.kozlowski@linaro.org Cc: gregkh@linuxfoundation.org, marc.ferland@sonatest.com, jeff.dagenais@gmail.com, rdunlap@infradead.org, linux-kernel@vger.kernel.org References: <20231130135232.191320-1-marc.ferland@sonatest.com> <20231130135232.191320-2-marc.ferland@sonatest.com> Content-Language: en-US From: Krzysztof Kozlowski Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJgPO8PBQkUX63hAAoJEBuTQ307 QWKbBn8P+QFxwl7pDsAKR1InemMAmuykCHl+XgC0LDqrsWhAH5TYeTVXGSyDsuZjHvj+FRP+ gZaEIYSw2Yf0e91U9HXo3RYhEwSmxUQ4Fjhc9qAwGKVPQf6YuQ5yy6pzI8brcKmHHOGrB3tP /MODPt81M1zpograAC2WTDzkICfHKj8LpXp45PylD99J9q0Y+gb04CG5/wXs+1hJy/dz0tYy iua4nCuSRbxnSHKBS5vvjosWWjWQXsRKd+zzXp6kfRHHpzJkhRwF6ArXi4XnQ+REnoTfM5Fk VmVmSQ3yFKKePEzoIriT1b2sXO0g5QXOAvFqB65LZjXG9jGJoVG6ZJrUV1MVK8vamKoVbUEe 0NlLl/tX96HLowHHoKhxEsbFzGzKiFLh7hyboTpy2whdonkDxpnv/H8wE9M3VW/fPgnL2nPe xaBLqyHxy9hA9JrZvxg3IQ61x7rtBWBUQPmEaK0azW+l3ysiNpBhISkZrsW3ZUdknWu87nh6 eTB7mR7xBcVxnomxWwJI4B0wuMwCPdgbV6YDUKCuSgRMUEiVry10xd9KLypR9Vfyn1AhROrq AubRPVeJBf9zR5UW1trJNfwVt3XmbHX50HCcHdEdCKiT9O+FiEcahIaWh9lihvO0ci0TtVGZ MCEtaCE80Q3Ma9RdHYB3uVF930jwquplFLNF+IBCn5JRzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmA872oFCRRflLYACgkQG5NDfTtBYpvScw/9GrqBrVLuJoJ52qBBKUBDo4E+5fU1bjt0 Gv0nh/hNJuecuRY6aemU6HOPNc2t8QHMSvwbSF+Vp9ZkOvrM36yUOufctoqON+wXrliEY0J4 ksR89ZILRRAold9Mh0YDqEJc1HmuxYLJ7lnbLYH1oui8bLbMBM8S2Uo9RKqV2GROLi44enVt vdrDvo+CxKj2K+d4cleCNiz5qbTxPUW/cgkwG0lJc4I4sso7l4XMDKn95c7JtNsuzqKvhEVS oic5by3fbUnuI0cemeizF4QdtX2uQxrP7RwHFBd+YUia7zCcz0//rv6FZmAxWZGy5arNl6Vm lQqNo7/Poh8WWfRS+xegBxc6hBXahpyUKphAKYkah+m+I0QToCfnGKnPqyYIMDEHCS/RfqA5 t8F+O56+oyLBAeWX7XcmyM6TGeVfb+OZVMJnZzK0s2VYAuI0Rl87FBFYgULdgqKV7R7WHzwD uZwJCLykjad45hsWcOGk3OcaAGQS6NDlfhM6O9aYNwGL6tGt/6BkRikNOs7VDEa4/HlbaSJo 7FgndGw1kWmkeL6oQh7wBvYll2buKod4qYntmNKEicoHGU+x91Gcan8mCoqhJkbqrL7+nXG2 5Q/GS5M9RFWS+nYyJh+c3OcfKqVcZQNANItt7+ULzdNJuhvTRRdC3g9hmCEuNSr+CLMdnRBY fv0= In-Reply-To: <20231130135232.191320-2-marc.ferland@sonatest.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/11/2023 14:52, marc.ferland@gmail.com wrote: > From: Marc Ferland > > The current ds_read_block function only supports block sizes up to > 128 bytes, which is the depth of the 'data out' fifo on the ds2490. > > Reading larger blocks will fail with a: -110 (ETIMEDOUT) from > usb_control_msg(). Example: > > $ dd if=/sys/bus/w1/devices/43-000000478756/eeprom bs=256 count=1 > > yields to the following message from the kernel: > > usb 5-1: Failed to write 1-wire data to ep0x2: err=-110. > > I discovered this issue while implementing support for the ds28ec20 > eeprom in the w1-2433 driver. This driver accepts reading blocks of > sizes up to the size of the entire memory (2560 bytes in the case of > the ds28ec20). Note that this issue _does not_ arises when the kernel > is configured with CONFIG_W1_SLAVE_DS2433_CRC enabled since in this > mode the driver reads one 32 byte block at a time (a single memory > page). > > Also, from the ds2490 datasheet (2995.pdf, page 22, BLOCK I/O > command): > > For a block write sequence the EP2 FIFO must be pre-filled with > data before command execution. Additionally, for block sizes > greater then the FIFO size, the FIFO content status must be > monitored by host SW so that additional data can be sent to the > FIFO when necessary. A similar EP3 FIFO content monitoring > requirement exists for block read sequences. During a block read > the number of bytes loaded into the EP3 FIFO must be monitored so > that the data can be read before the FIFO overflows. > > Breaking the buffer in 128 bytes blocks and simply calling the > original code sequence has solved the issue for me. > > Tested with a DS1490F usb<->one-wire adapter and both the DS28EC20 and > DS2433 eeprom memories. > > Note: The v1 of this patch changed both the ds_read_block and > ds_write_block functions, but since I don't have any way to test the > 'write' part with writes bigger than a page size (maximum accepted by > my eeprom), I preferred not to make any assumptions and I just > removed that part. Drop that paragraph, not really helping to understand the commit once accepted. > > Signed-off-by: Marc Ferland > --- > drivers/w1/masters/ds2490.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > > diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c > index 5f5b97e24700..b6e244992c15 100644 > --- a/drivers/w1/masters/ds2490.c > +++ b/drivers/w1/masters/ds2490.c > @@ -98,6 +98,8 @@ > #define ST_EPOF 0x80 > /* Status transfer size, 16 bytes status, 16 byte result flags */ > #define ST_SIZE 0x20 > +/* 1-wire data i/o fifo size, 128 bytes */ > +#define FIFO_SIZE 0x80 > > /* Result Register flags */ > #define RR_DETECT 0xA5 /* New device detected */ > @@ -614,14 +616,11 @@ static int ds_read_byte(struct ds_device *dev, u8 *byte) > return 0; > } > > -static int ds_read_block(struct ds_device *dev, u8 *buf, int len) > +static int __read_block(struct ds_device *dev, u8 *buf, int len) Drop __ and name the function descriptive. It's confusing to have two times read_block(). Just name them according to what they really do. Best regards, Krzysztof