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H A D | sdhci_am654.c | 7ca0f166 Tue Aug 25 12:00:15 CDT 2020 Faiz Abbas <faiz_abbas@ti.com> mmc: sdhci_am654: Add workaround for card detect debounce timer
There is a one time delay because of a card detect debounce timer in the controller IP. This timer runs as soon as power is applied to the module regardless of whether a card is present or not and any writes to SDHCI_POWER_ON will return 0 before it expires. This timeout has been measured to be about 1 second in am654x and j721e.
Write-and-read-back in a loop on SDHCI_POWER_ON for a maximum of 1.5 seconds to make sure that the controller actually powers on.
Signed-off-by: Faiz Abbas <faiz_abbas@ti.com> Link: https://lore.kernel.org/r/20200825170015.32285-1-faiz_abbas@ti.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 7ca0f166 Tue Aug 25 12:00:15 CDT 2020 Faiz Abbas <faiz_abbas@ti.com> mmc: sdhci_am654: Add workaround for card detect debounce timer There is a one time delay because of a card detect debounce timer in the controller IP. This timer runs as soon as power is applied to the module regardless of whether a card is present or not and any writes to SDHCI_POWER_ON will return 0 before it expires. This timeout has been measured to be about 1 second in am654x and j721e. Write-and-read-back in a loop on SDHCI_POWER_ON for a maximum of 1.5 seconds to make sure that the controller actually powers on. Signed-off-by: Faiz Abbas <faiz_abbas@ti.com> Link: https://lore.kernel.org/r/20200825170015.32285-1-faiz_abbas@ti.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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