@@ -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.
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 <mauro.lima@eclypsium.com> --- 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