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([186.122.48.201]) by smtp.gmail.com with ESMTPSA id m128-20020acabc86000000b0037880fdb1f6sm2308896oif.24.2023.02.10.08.42.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Feb 2023 08:42:07 -0800 (PST) From: Mauro Lima To: mika.westerberg@linux.intel.com Cc: broonie@kernel.org, michael@walle.cc, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Mauro Lima Subject: [PATCH v2] spi: intel: Update help text of PCI and Platform drivers Date: Fri, 10 Feb 2023 13:41:58 -0300 Message-Id: <20230210164158.211065-1-mauro.lima@eclypsium.com> X-Mailer: git-send-email 2.39.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Modern intel hardware uses controllers that work in hardware sequencing mode. In this mode, the controller exposes a subset of operations, like read, write and erase, making it easier and less error-prone for use. On the other hand, most of the controllers handled by the platform driver use software sequencing that exposes the entire set of operations i.e. exposes the low level SPI-NOR opcodes to the software for use. Update PCI and Platform help text with this information. Signed-off-by: Mauro Lima Acked-by: Mika Westerberg --- For the record of the base commit: Given that the PCI driver handles controllers that only work with hardware sequencing, we can remove the dangerous tag. This patch is the second part of Mika's suggestion [1]. The first part was accepted in [2]. [1] https://lore.kernel.org/r/Y1d9glOgHsQlZe2L@black.fi.intel.com/ [2] https://lore.kernel.org/linux-spi/20230201205455.550308-1-mauro.lima@eclypsium.com/ This patch continues the work addressing the comments in the previous patch adding information about hardware and software sequencing. Discussion: https://lore.kernel.org/r/20230206183143.75274-1-mauro.lima@eclypsium.com/ v1->v2: Addressing comments from the review of v1 Link: https://lore.kernel.org/r/20230208175253.117714-1-mauro.lima@eclypsium.com/ drivers/spi/Kconfig | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) base-commit: 7db738b5fea4533fa217dfb05c506c15bd0964d9 diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 3a362c450cb6..db033d424bb5 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -454,13 +454,12 @@ config SPI_INTEL_PCI select SPI_INTEL help This enables PCI support for the Intel PCH/PCU SPI controller in - master mode. This controller is present in modern Intel hardware - and is used to hold BIOS and other persistent settings. This - driver only supports hardware sequencing mode. Using this - driver it is possible to upgrade BIOS directly from Linux. - - Say N here unless you know what you are doing. Overwriting the - SPI flash may render the system unbootable. + master mode. This controller is used to hold BIOS and other + persistent settings. Controllers present in modern Intel hardware + only work in hardware sequencing mode, this means that the + controller exposes a subset of operations that makes it safer to + use. Using this driver it is possible to upgrade BIOS directly + from Linux. To compile this driver as a module, choose M here: the module will be called spi-intel-pci. @@ -473,9 +472,10 @@ config SPI_INTEL_PLATFORM help This enables platform support for the Intel PCH/PCU SPI controller in master mode that is used to hold BIOS and other - persistent settings. Most of these controllers are using - software sequencing mode. Using this driver it is possible to - upgrade BIOS directly from Linux. + persistent settings. Most of these controllers work in + software sequencing mode, which means that the controller + exposes the low level SPI-NOR opcodes to the software. Using + this driver it is possible to upgrade BIOS directly from Linux. Say N here unless you know what you are doing. Overwriting the SPI flash may render the system unbootable.