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Kernel: Wait for transactions to complete before stopping SD clock

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This commit is contained in:
Daniel Bertalan 2023-06-24 09:24:02 +02:00 • committed by Jelle Raaijmakers
parent b90a20aee6
commit 6185a19618
2 changed files with 12 additions and 4 deletions
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14
Kernel/Devices/Storage/SD/SDHostController.cpp
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@ -136,7 +136,7 @@ ErrorOr<NonnullLockRefPtr<SDMemoryCard>> SDHostController::try_initialize_insert
// NOTE: The SDHC might already have been initialized (e.g. by the bootloader), let's reset it to a known configuration
if (is_sd_clock_enabled())
sd_clock_stop();
TRY(sd_clock_stop());
TRY(sd_clock_supply(400000));
// PLSS 4.2.3: "Card Initialization and Identification Process"
@ -459,12 +459,20 @@ ErrorOr<void> SDHostController::sd_clock_supply(u32 frequency)
return {};
}
void SDHostController::sd_clock_stop()
ErrorOr<void> SDHostController::sd_clock_stop()
{
// SDHC 3.2.2: "SD Clock Stop Sequence"
// The Host Driver shall not clear SD Clock Enable while an SD transaction is executing on the SD Bus --
// namely, while either Command Inhibit (DAT) or Command Inhibit (CMD) in the Present State register
// is set to 1
if (!retry_with_timeout([&] { return !m_registers->present_state.command_inhibit_dat && !m_registers->present_state.command_inhibit_cmd; })) {
return EIO;
}
// 1. Set SD Clock Enable in the Clock Control register to 0
m_registers->host_configuration_1 = m_registers->host_configuration_1 & ~sd_clock_enable;
return {};
}
ErrorOr<void> SDHostController::sd_clock_frequency_change(u32 new_frequency)
@ -472,7 +480,7 @@ ErrorOr<void> SDHostController::sd_clock_frequency_change(u32 new_frequency)
// SDHC 3.2.3: "SD Clock Frequency Change Sequence"
// 1. Execute the SD Clock Stop Sequence
sd_clock_stop();
TRY(sd_clock_stop());
// 2. Execute the SD Clock Supply Sequence
return sd_clock_supply(new_frequency);