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Merge pull request #10799 from hydra/bf-sdcard-fixes-2

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Michael Keller 2021-09-10 03:03:53 +12:00
parent 089cae0af1
commit 0bef24a579
6 changed files with 89 additions and 12 deletions
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12
lib/main/STM32H7/Drivers/STM32H7xx_HAL_Driver/Src/stm32h7xx_ll_sdmmc.c
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@ -446,13 +446,13 @@ HAL_StatusTypeDef SDMMC_ConfigData(SDMMC_TypeDef *SDMMCx, SDMMC_DataInitTypeDef*
// DC - See errata 2.11.4 - 8 SDMMC clock cycles must elapse before DTEN can be set.
// 32U below is used as a VERY rough guess that the SDMMC clock is 1/4 of the sytem clock, 8 * 4 = 32 and that the
// assembly below only takes 1 CPU cycle to run. All of which will be wrong, but right enough most of the time, especially
// when considering other processing overheads.
// loop code below only takes 2 CPU cycles to run. All of which will likely be wrong, but right enough most of the time.
// It's important that the code isn't optimized-out by the compiler or linker too, see
// https://stackoverflow.com/questions/7083482/how-to-prevent-gcc-from-optimizing-out-a-busy-wait-loop
register uint32_t count = 32U;
do
{
count--;
} while(count > 0);
for (unsigned i = 0; i < count; i++) {
__asm__ volatile("" : "+g" (i) : :);
}
// DC - See errata 2.11.4
/* Write to SDMMC DCTRL */