From: Mark Brown <broonie@kernel.org>
To: Alain Volmat <alain.volmat@st.com>
Cc: amelie.delaunay@st.com, alexandre.torgue@st.com,
linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org,
mcoquelin.stm32@gmail.com, fabrice.gasnier@st.com,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 03/18] spi: stm32h7: remove unused mode fault MODF event handling
Date: Wed, 5 Aug 2020 11:51:04 +0100 [thread overview]
Message-ID: <20200805105104.GC5556@sirena.org.uk> (raw)
In-Reply-To: <1596610933-32599-4-git-send-email-alain.volmat@st.com>
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On Wed, Aug 05, 2020 at 09:01:58AM +0200, Alain Volmat wrote:
> From: Antonio Borneo <antonio.borneo@st.com>
> Accordingly to STM32H7 document RM0433, "mode fault" MODF is
> a special mode to handle a spi bus with multiple masters, in
> which each master has to "detect" if another master enables
> its CS to take control of the bus. Once this is detected,
> all other masters has to temporarily switch to "slave" mode.
> Such multi-master mode is not supported in Linux and this
> driver properly disables the mode by setting the bits
> SPI_CR1_SSI and SPI_CFG2_SSM, thus forcing a master only
> operating mode.
> In this condition, we will never receive an interrupt due to
> MODF event and we do not need to handle it.
> Remove all the unused code around handling MODF events.
What does having this cost us? Hopefully it's not doing much but if
something goes wrong with the hardware and this does get flagged up for
some reason it'd be good to know about it. It doesn't seem to be having
a big impact on the code or anything.
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next prev parent reply other threads:[~2020-08-05 10:52 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-05 7:01 [PATCH 00/18] spi: stm32: various driver enhancements Alain Volmat
2020-08-05 7:01 ` [PATCH 01/18] spi: stm32-spi: driver uses reset controller only at init Alain Volmat
2020-08-05 7:01 ` [PATCH 02/18] spi: stm32-spi: defer probe for reset Alain Volmat
2020-08-05 10:49 ` Mark Brown
2020-08-07 13:42 ` Alain Volmat
2020-08-07 14:01 ` Mark Brown
2020-08-05 7:01 ` [PATCH 03/18] spi: stm32h7: remove unused mode fault MODF event handling Alain Volmat
2020-08-05 10:51 ` Mark Brown [this message]
2020-08-05 7:01 ` [PATCH 04/18] spi: stm32: use bitfield macros Alain Volmat
2020-08-05 7:02 ` [PATCH 05/18] spi: stm32h7: replace private SPI_1HZ_NS with NSEC_PER_SEC Alain Volmat
2020-08-05 7:02 ` [PATCH 06/18] spi: stm32h7: fix irq handler Alain Volmat
2020-08-05 7:02 ` [PATCH 07/18] spi: stm32h7: rework rx fifo read function Alain Volmat
2020-08-05 7:02 ` [PATCH 08/18] spi: stm32h7: fix dbg/warn/err conditions in irq handler Alain Volmat
2020-08-05 7:02 ` [PATCH 09/18] spi: stm32h7: fix race condition at end of transfer Alain Volmat
2020-08-05 10:53 ` Mark Brown
2020-08-05 7:02 ` [PATCH 10/18] spi: stm32: wait for completion in transfer_one() Alain Volmat
2020-08-05 10:58 ` Mark Brown
2020-08-05 7:02 ` [PATCH 11/18] spi: stm32: fix fifo threshold level in case of short transfer Alain Volmat
2020-08-05 10:59 ` Mark Brown
2020-08-05 7:02 ` [PATCH 12/18] spi: stm32: move spi disable out of irq handler Alain Volmat
2020-08-05 11:01 ` Mark Brown
2020-08-05 7:02 ` [PATCH 13/18] spi: stm32h7: fix handling of dma transfer completed Alain Volmat
2020-08-05 11:02 ` Mark Brown
2020-08-05 7:02 ` [PATCH 14/18] spi: stm32: improve suspend/resume management Alain Volmat
2020-08-05 7:02 ` [PATCH 15/18] spi: stm32: fix stm32_spi_prepare_mbr in case of odd clk_rate Alain Volmat
2020-08-05 11:02 ` Mark Brown
2020-08-05 7:02 ` [PATCH 16/18] spi: stm32: always perform registers configuration prior to transfer Alain Volmat
2020-08-05 11:03 ` Mark Brown
2020-08-05 7:02 ` [PATCH 17/18] spi: stm32: properly handle 0 byte transfer Alain Volmat
2020-08-05 7:02 ` [PATCH 18/18] spi: stm32h7: ensure message are smaller than max size Alain Volmat
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