mmc: sdhci: Disable SD card clock before changing parameters#272
Open
erickshepherdNI wants to merge 1 commit intoni:nilrt/master/6.12from
Open
mmc: sdhci: Disable SD card clock before changing parameters#272erickshepherdNI wants to merge 1 commit intoni:nilrt/master/6.12from
erickshepherdNI wants to merge 1 commit intoni:nilrt/master/6.12from
Conversation
Per the SD Host Controller Simplified Specification v4.20 §3.2.3, change the SD card clock parameters only after first disabling the external card clock. Doing this fixes a spurious clock pulse on Baytrail and Apollo Lake SD controllers which otherwise breaks voltage switching with a specific Swissbit SD card. This change is limited to Intel host controllers to avoid an issue reported on ARM64 devices. Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com> Signed-off-by: Brad Mouring <brad.mouring@ni.com> Signed-off-by: Erick Shepherd <erick.shepherd@ni.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Link: https://lore.kernel.org/r/20250724185354.815888-1-erick.shepherd@ni.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> (cherry picked from commit 5f755ba)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Per the SD Host Controller Simplified Specification v4.20 §3.2.3, change the SD card clock parameters only after first disabling the external card clock. Doing this fixes a spurious clock pulse on Baytrail and Apollo Lake SD controllers which otherwise breaks voltage switching with a specific Swissbit SD card. This change is limited to Intel host controllers to avoid an issue reported on ARM64 devices.
Acked-by: Adrian Hunter adrian.hunter@intel.com
Link: https://lore.kernel.org/r/20250724185354.815888-1-erick.shepherd@ni.com
(cherry picked from commit 5f755ba)