From: Mark Brown <broonie@kernel.org>
To: Serge Semin <fancer.lancer@gmail.com>
Cc: Sean Anderson <seanga2@gmail.com>,
Damien Le Moal <damien.lemoal@wdc.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
linux-riscv@lists.infradead.org, Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
devicetree@vger.kernel.org, linux-spi@vger.kernel.org,
Stephen Boyd <sboyd@kernel.org>,
linux-clk@vger.kernel.org,
Linus Walleij <linus.walleij@linaro.org>,
linux-gpio@vger.kernel.org,
Philipp Zabel <p.zabel@pengutronix.de>
Subject: Re: [PATCH 03/32] spi: dw: Fix driving MOSI low while recieving
Date: Mon, 9 Nov 2020 20:29:09 +0000 [thread overview]
Message-ID: <20201109202909.GM6380@sirena.org.uk> (raw)
In-Reply-To: <20201109201744.zlxwur4p3ejbraup@mobilestation>
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On Mon, Nov 09, 2020 at 11:17:44PM +0300, Serge Semin wrote:
> On Mon, Nov 09, 2020 at 02:40:01PM -0500, Sean Anderson wrote:
> > On 11/9/20 2:19 PM, Serge Semin wrote:
> > > Getting back to the patch. In fact I don't really see how the
> > > Receive-only mode will help us with solving the problem noted in the
> > > patch log.
> > Shouldn't it put MOSI into High-Z like when the device is idle? The
> > issue is mainly that the idle state and RX state are different.
> AFAICS the manual doesn't say anything about High-Z, but only: "In
> receive-only mode, transmitted data are not valid. After the first
> write to the transmit FIFO, the same word is retransmitted for the
> duration of the transfer."
This is the sort of behaviour I would expect, and I'd expect that going
high Z could potentially cause electrical problems as the line won't be
being driven when it's been designed to be an output from the controller
so it's probably not desirable to do that.
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WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org>
To: Serge Semin <fancer.lancer@gmail.com>
Cc: devicetree@vger.kernel.org,
Damien Le Moal <damien.lemoal@wdc.com>,
Stephen Boyd <sboyd@kernel.org>,
Linus Walleij <linus.walleij@linaro.org>,
Sean Anderson <seanga2@gmail.com>,
linux-gpio@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Philipp Zabel <p.zabel@pengutronix.de>,
linux-riscv@lists.infradead.org, linux-spi@vger.kernel.org,
Frank Rowand <frowand.list@gmail.com>,
linux-clk@vger.kernel.org
Subject: Re: [PATCH 03/32] spi: dw: Fix driving MOSI low while recieving
Date: Mon, 9 Nov 2020 20:29:09 +0000 [thread overview]
Message-ID: <20201109202909.GM6380@sirena.org.uk> (raw)
In-Reply-To: <20201109201744.zlxwur4p3ejbraup@mobilestation>
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On Mon, Nov 09, 2020 at 11:17:44PM +0300, Serge Semin wrote:
> On Mon, Nov 09, 2020 at 02:40:01PM -0500, Sean Anderson wrote:
> > On 11/9/20 2:19 PM, Serge Semin wrote:
> > > Getting back to the patch. In fact I don't really see how the
> > > Receive-only mode will help us with solving the problem noted in the
> > > patch log.
> > Shouldn't it put MOSI into High-Z like when the device is idle? The
> > issue is mainly that the idle state and RX state are different.
> AFAICS the manual doesn't say anything about High-Z, but only: "In
> receive-only mode, transmitted data are not valid. After the first
> write to the transmit FIFO, the same word is retransmitted for the
> duration of the transfer."
This is the sort of behaviour I would expect, and I'd expect that going
high Z could potentially cause electrical problems as the line won't be
being driven when it's been designed to be an output from the controller
so it's probably not desirable to do that.
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next prev parent reply other threads:[~2020-11-09 20:29 UTC|newest]
Thread overview: 297+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-07 8:13 [PATCH 00/32] RISC-V Kendryte K210 support improvments Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-07 8:13 ` [PATCH 01/32] of: Fix property supplier parsing Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-09 15:05 ` Serge Semin
2020-11-09 15:05 ` Serge Semin
2020-11-09 15:14 ` Andy Shevchenko
2020-11-09 15:14 ` Andy Shevchenko
2020-11-09 17:44 ` Serge Semin
2020-11-09 17:44 ` Serge Semin
2020-11-09 20:52 ` Rob Herring
2020-11-09 20:52 ` Rob Herring
2020-11-16 7:30 ` Damien Le Moal
2020-11-16 7:30 ` Damien Le Moal
2020-11-16 22:06 ` Serge Semin
2020-11-16 22:06 ` Serge Semin
2020-11-07 8:13 ` [PATCH 02/32] spi: dw: Add support for 32-bits ctrlr0 layout Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-07 13:28 ` Sean Anderson
2020-11-07 13:28 ` Sean Anderson
2020-11-09 14:25 ` Serge Semin
2020-11-09 14:25 ` Serge Semin
2020-11-09 14:33 ` Sean Anderson
2020-11-09 14:33 ` Sean Anderson
2020-11-09 14:35 ` Sean Anderson
2020-11-09 14:35 ` Sean Anderson
2020-11-09 14:40 ` Andy Shevchenko
2020-11-09 14:40 ` Andy Shevchenko
2020-11-09 14:41 ` Andy Shevchenko
2020-11-09 14:41 ` Andy Shevchenko
2020-11-09 14:49 ` Sean Anderson
2020-11-09 14:49 ` Sean Anderson
2020-11-09 15:10 ` Andy Shevchenko
2020-11-09 15:10 ` Andy Shevchenko
2020-11-09 14:36 ` Andy Shevchenko
2020-11-09 14:36 ` Andy Shevchenko
2020-11-09 17:56 ` Serge Semin
2020-11-09 17:56 ` Serge Semin
2020-11-07 8:13 ` [PATCH 03/32] spi: dw: Fix driving MOSI low while recieving Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-07 13:30 ` Sean Anderson
2020-11-07 13:30 ` Sean Anderson
2020-11-09 13:29 ` Mark Brown
2020-11-09 13:29 ` Mark Brown
2020-11-09 13:47 ` Sean Anderson
2020-11-09 13:47 ` Sean Anderson
2020-11-09 14:14 ` Mark Brown
2020-11-09 14:14 ` Mark Brown
2020-11-09 14:48 ` Serge Semin
2020-11-09 14:48 ` Serge Semin
2020-11-09 16:45 ` Mark Brown
2020-11-09 16:45 ` Mark Brown
2020-11-09 19:19 ` Serge Semin
2020-11-09 19:19 ` Serge Semin
2020-11-09 19:40 ` Sean Anderson
2020-11-09 19:40 ` Sean Anderson
2020-11-09 20:17 ` Serge Semin
2020-11-09 20:17 ` Serge Semin
2020-11-09 20:29 ` Mark Brown [this message]
2020-11-09 20:29 ` Mark Brown
2020-11-09 20:20 ` Mark Brown
2020-11-09 20:20 ` Mark Brown
2020-11-09 21:05 ` Serge Semin
2020-11-09 21:05 ` Serge Semin
2020-11-10 13:43 ` Mark Brown
2020-11-10 13:43 ` Mark Brown
2020-11-07 8:13 ` [PATCH 04/32] spi: dw: Introduce polling device tree property Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-09 16:04 ` Mark Brown
2020-11-09 16:04 ` Mark Brown
2020-11-09 19:59 ` Serge Semin
2020-11-09 19:59 ` Serge Semin
2020-11-13 9:22 ` Damien Le Moal
2020-11-13 9:22 ` Damien Le Moal
2020-11-15 16:01 ` Serge Semin
2020-11-15 16:01 ` Serge Semin
2020-11-16 7:47 ` Damien Le Moal
2020-11-16 7:47 ` Damien Le Moal
2020-11-16 12:33 ` Mark Brown
2020-11-16 12:33 ` Mark Brown
2020-11-16 21:55 ` Serge Semin
2020-11-16 21:55 ` Serge Semin
2020-11-17 14:44 ` Damien Le Moal
2020-11-17 14:44 ` Damien Le Moal
2020-11-17 18:26 ` Serge Semin
2020-11-17 18:26 ` Serge Semin
2020-11-18 4:41 ` Damien Le Moal
2020-11-18 4:41 ` Damien Le Moal
2020-11-18 15:16 ` Serge Semin
2020-11-18 15:16 ` Serge Semin
2020-11-19 5:12 ` Damien Le Moal
2020-11-19 5:12 ` Damien Le Moal
2020-11-19 8:51 ` Serge Semin
2020-11-19 8:51 ` Serge Semin
2020-11-19 8:57 ` Damien Le Moal
2020-11-19 8:57 ` Damien Le Moal
2020-11-07 8:13 ` [PATCH 05/32] spi: dw: Introduce DW_SPI_CAP_POLL_NODELAY Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-09 14:03 ` Mark Brown
2020-11-09 14:03 ` Mark Brown
2020-11-09 20:45 ` Serge Semin
2020-11-09 20:45 ` Serge Semin
2020-11-07 8:13 ` [PATCH 06/32] spi: dw: Add support for the Kendryte K210 SoC Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-07 13:31 ` Sean Anderson
2020-11-07 13:31 ` Sean Anderson
2020-11-07 13:42 ` Damien Le Moal
2020-11-07 13:42 ` Damien Le Moal
2020-11-07 13:52 ` Sean Anderson
2020-11-07 13:52 ` Sean Anderson
2020-11-09 14:15 ` Mark Brown
2020-11-09 14:15 ` Mark Brown
2020-11-13 8:00 ` Damien Le Moal
2020-11-13 8:00 ` Damien Le Moal
2020-11-09 21:21 ` Serge Semin
2020-11-09 21:21 ` Serge Semin
2020-11-09 21:39 ` Damien Le Moal
2020-11-09 21:39 ` Damien Le Moal
2020-11-09 21:55 ` Rob Herring
2020-11-09 21:55 ` Rob Herring
2020-11-09 22:00 ` Damien Le Moal
2020-11-09 22:00 ` Damien Le Moal
2020-11-09 23:07 ` Rob Herring
2020-11-09 23:07 ` Rob Herring
2020-11-10 0:35 ` Damien Le Moal
2020-11-10 0:35 ` Damien Le Moal
2020-11-07 8:13 ` [PATCH 07/32] dt-bindings: Update DW SPI device tree bindings Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-07 8:13 ` [PATCH 08/32] riscv: Fix kernel time_init() Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-12 7:21 ` Atish Patra
2020-11-12 7:21 ` Atish Patra
2020-11-13 7:31 ` Stephen Boyd
2020-11-13 7:31 ` Stephen Boyd
2020-11-13 7:40 ` Damien Le Moal
2020-11-13 7:40 ` Damien Le Moal
2020-11-13 7:53 ` Stephen Boyd
2020-11-13 7:53 ` Stephen Boyd
2020-11-13 7:57 ` Damien Le Moal
2020-11-13 7:57 ` Damien Le Moal
2020-11-13 8:11 ` Stephen Boyd
2020-11-13 8:11 ` Stephen Boyd
2020-11-13 8:23 ` Damien Le Moal
2020-11-13 8:23 ` Damien Le Moal
2020-11-16 7:06 ` Stephen Boyd
2020-11-16 7:06 ` Stephen Boyd
2020-11-16 7:18 ` Damien Le Moal
2020-11-16 7:18 ` Damien Le Moal
2020-11-07 8:13 ` [PATCH 09/32] riscv: Fix SiFive gpio probe Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-10 14:39 ` Linus Walleij
2020-11-10 14:39 ` Linus Walleij
2020-11-11 7:00 ` Damien Le Moal
2020-11-11 7:00 ` Damien Le Moal
2020-11-11 8:54 ` Linus Walleij
2020-11-11 8:54 ` Linus Walleij
2020-11-11 8:56 ` Damien Le Moal
2020-11-11 8:56 ` Damien Le Moal
2020-11-07 8:13 ` [PATCH 10/32] riscv: Fix sifive serial driver Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-07 8:13 ` [PATCH 11/32] riscv: Enable interrupts during syscalls with M-Mode Damien Le Moal
2020-11-07 8:13 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 12/32] riscv: Automatically select sysctl config options Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 13/32] riscv: Fix builtin DTB handling Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-15 4:17 ` kernel test robot
2020-11-15 4:17 ` kernel test robot
2020-11-15 4:17 ` kernel test robot
2020-11-07 8:14 ` [PATCH 14/32] dt-bindings: Define all Kendryte K210 clock IDs Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 13:33 ` Sean Anderson
2020-11-07 13:33 ` Sean Anderson
2020-11-07 8:14 ` [PATCH 15/32] dt-bindings: Define Kendryte K210 sysctl registers Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 13:34 ` Sean Anderson
2020-11-07 13:34 ` Sean Anderson
2020-11-09 21:59 ` Rob Herring
2020-11-09 21:59 ` Rob Herring
2020-11-09 22:10 ` Sean Anderson
2020-11-09 22:10 ` Sean Anderson
2020-11-09 23:01 ` Rob Herring
2020-11-09 23:01 ` Rob Herring
2020-11-07 8:14 ` [PATCH 16/32] dt-bindings: Define Kendryte K210 pin functions Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 13:38 ` Sean Anderson
2020-11-07 13:38 ` Sean Anderson
2020-11-07 8:14 ` [PATCH 17/32] dt-bindings: Define Kendryte K210 reset signals Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 13:38 ` Sean Anderson
2020-11-07 13:38 ` Sean Anderson
2020-11-07 8:14 ` [PATCH 18/32] riscv: Add Kendryte K210 SoC clock driver Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 13:48 ` Sean Anderson
2020-11-07 13:48 ` Sean Anderson
2020-11-13 8:14 ` Damien Le Moal
2020-11-13 8:14 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 19/32] riscv: Add Kendryte K210 SoC reset controller Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 13:58 ` Sean Anderson
2020-11-07 13:58 ` Sean Anderson
2020-11-07 8:14 ` [PATCH 20/32] riscv: Add Kendryte K210 FPIOA pinctrl driver Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-09 18:48 ` kernel test robot
2020-11-09 18:48 ` kernel test robot
2020-11-09 18:48 ` kernel test robot
2020-11-15 0:28 ` kernel test robot
2020-11-15 0:28 ` kernel test robot
2020-11-15 0:28 ` kernel test robot
2020-11-24 8:43 ` Linus Walleij
2020-11-24 8:43 ` Linus Walleij
2020-11-24 8:53 ` Damien Le Moal
2020-11-24 8:53 ` Damien Le Moal
2020-11-29 21:33 ` Linus Walleij
2020-11-29 21:33 ` Linus Walleij
2020-11-30 3:13 ` Damien Le Moal
2020-11-30 3:13 ` Damien Le Moal
2020-11-30 7:05 ` Serge Semin
2020-11-30 7:05 ` Serge Semin
2020-11-30 7:27 ` Damien Le Moal
2020-11-30 7:27 ` Damien Le Moal
2020-11-24 8:56 ` Damien Le Moal
2020-11-24 8:56 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 21/32] dt-bindings: Add Kendryte and Canaan vendor prefix Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:03 ` Sean Anderson
2020-11-07 14:03 ` Sean Anderson
2020-11-13 8:17 ` Damien Le Moal
2020-11-13 8:17 ` Damien Le Moal
2020-11-09 22:01 ` Rob Herring
2020-11-09 22:01 ` Rob Herring
2020-11-09 22:04 ` Damien Le Moal
2020-11-09 22:04 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 22/32] dt-binding: Document kendryte,k210-sysctl bindings Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:05 ` Sean Anderson
2020-11-07 14:05 ` Sean Anderson
2020-11-09 15:32 ` Rob Herring
2020-11-09 15:32 ` Rob Herring
2020-11-07 8:14 ` [PATCH 23/32] dt-binding: Document kendryte,k210-clk bindings Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:05 ` Sean Anderson
2020-11-07 14:05 ` Sean Anderson
2020-11-09 21:58 ` Rob Herring
2020-11-09 21:58 ` Rob Herring
2020-11-07 8:14 ` [PATCH 24/32] dt-bindings: Document kendryte,k210-fpioa bindings Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:06 ` Sean Anderson
2020-11-07 14:06 ` Sean Anderson
2020-11-09 15:32 ` Rob Herring
2020-11-09 15:32 ` Rob Herring
2020-11-09 15:36 ` Rob Herring
2020-11-09 15:36 ` Rob Herring
2020-11-09 15:45 ` Sean Anderson
2020-11-09 15:45 ` Sean Anderson
2020-11-11 14:32 ` Rob Herring
2020-11-11 14:32 ` Rob Herring
2020-11-11 15:06 ` Damien Le Moal
2020-11-11 15:06 ` Damien Le Moal
2020-11-12 11:03 ` Damien Le Moal
2020-11-12 11:03 ` Damien Le Moal
2020-11-19 10:57 ` Geert Uytterhoeven
2020-11-19 10:57 ` Geert Uytterhoeven
2020-11-19 11:22 ` Damien Le Moal
2020-11-19 11:22 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 25/32] dt-bindings: Document kendryte,k210-rst bindings Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:07 ` Sean Anderson
2020-11-07 14:07 ` Sean Anderson
2020-11-09 15:37 ` Rob Herring
2020-11-09 15:37 ` Rob Herring
2020-11-09 15:41 ` Rob Herring
2020-11-09 15:41 ` Rob Herring
2020-11-07 8:14 ` [PATCH 26/32] riscv: Update Kendryte K210 device tree Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:08 ` Sean Anderson
2020-11-07 14:08 ` Sean Anderson
2020-11-07 8:14 ` [PATCH 27/32] riscv: Add SiPeed MAIX BiT board " Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:13 ` Sean Anderson
2020-11-07 14:13 ` Sean Anderson
2020-11-07 8:14 ` [PATCH 28/32] riscv: Add SiPeed MAIX DOCK " Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 29/32] riscv: Add SiPeed MAIX GO " Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 30/32] riscv: Add SiPeed MAIXDUINO " Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 14:14 ` Sean Anderson
2020-11-07 14:14 ` Sean Anderson
2020-11-07 8:14 ` [PATCH 31/32] riscv: Add Kendryte KD233 " Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-07 8:14 ` [PATCH 32/32] riscv: Update Kendryte K210 defconfig Damien Le Moal
2020-11-07 8:14 ` Damien Le Moal
2020-11-09 12:51 ` [PATCH 00/32] RISC-V Kendryte K210 support improvments Mark Brown
2020-11-09 12:51 ` Mark Brown
2020-11-09 12:55 ` Damien Le Moal
2020-11-09 12:55 ` Damien Le Moal
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