Attention is currently required from: Raul Rangel, Furquan Shaikh, Karthik Ramasubramanian, Felix Held.
Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/56645 )
Change subject: mb/google/guybrush: Switch from 33MHz to 66MHz SPI Speed
......................................................................
Patch Set 3:
(1 comment)
File src/mainboard/google/guybrush/variants/baseboard/devicetree.cb:
https://review.coreboot.org/c/coreboot/+/56645/comment/5d04a145_9645bcf8
PS3, Line 13: 33M
Makes sense. Thanks Felix! I think most parts support upto 50MHz for normal speed. […]
The way I remember it from older FCH, MMIO access right below 4 GiB will use either .normal_speed or .fast_speed while everything through the SPI driver layer will use .altio_speed.
In spi_ctrlr_xfer() register SPI_CMD_CODE 0x45 aliases/shadows 0x0 named SpiOpCode:
SpiOpCode. Read-write. Reset: 0. Specifies the SPI opcode in alternate program method.
We can find some old 3V parts marketed as dual-IO and 80MHz, which might fail with 66MHz as .fast_speed or .altio_speed. One example -- SST25VF064C, EOL 2015. If some of this change is pushed to older agesa/hudson better keep the default to 33MHz on all boards.
--
To view, visit
https://review.coreboot.org/c/coreboot/+/56645
To unsubscribe, or for help writing mail filters, visit
https://review.coreboot.org/settings
Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-Change-Id: Icc5c0580ed0d19f1fffce59df3888dd7963255a1
Gerrit-Change-Number: 56645
Gerrit-PatchSet: 3
Gerrit-Owner: Karthik Ramasubramanian
kramasub@google.com
Gerrit-Reviewer: Felix Held
felix-coreboot@felixheld.de
Gerrit-Reviewer: Furquan Shaikh
furquan@google.com
Gerrit-Reviewer: Karthik Ramasubramanian
kramasub@google.com
Gerrit-Reviewer: Martin Roth
martinroth@google.com
Gerrit-Reviewer: Paul Menzel
paulepanter@mailbox.org
Gerrit-Reviewer: Raul Rangel
rrangel@chromium.org
Gerrit-Reviewer: build bot (Jenkins)
no-reply@coreboot.org
Gerrit-CC: Kyösti Mälkki
kyosti.malkki@gmail.com
Gerrit-Attention: Raul Rangel
rrangel@chromium.org
Gerrit-Attention: Furquan Shaikh
furquan@google.com
Gerrit-Attention: Karthik Ramasubramanian
kramasub@google.com
Gerrit-Attention: Felix Held
felix-coreboot@felixheld.de
Gerrit-Comment-Date: Mon, 09 Aug 2021 05:32:55 +0000
Gerrit-HasComments: Yes
Gerrit-Has-Labels: No
Comment-In-Reply-To: Furquan Shaikh
furquan@google.com
Comment-In-Reply-To: Felix Held
felix-coreboot@felixheld.de
Gerrit-MessageType: comment