2017-10-26 15:55 GMT+02:00 Ard Biesheuvel <ard.biesheu...@linaro.org>: > On 26 October 2017 at 14:54, Marcin Wojtas <m...@semihalf.com> wrote: >> 2017-10-26 15:46 GMT+02:00 Leif Lindholm <leif.lindh...@linaro.org>: >>> On Thu, Oct 26, 2017 at 03:19:36AM +0200, Marcin Wojtas wrote: >>>> Incorrectly the clock divisor was calculated relatively >>>> to 255MHz instead of actual 400MHz. >>> >>> This describes the specific symptom, not the problem with the existing >>> code. >>> >>>> Fix this. >>>> >>>> Contributed-under: TianoCore Contribution Agreement 1.1 >>>> Signed-off-by: Marcin Wojtas <m...@semihalf.com> >>>> --- >>>> Platform/Marvell/Drivers/SdMmc/XenonDxe/SdMmcPciHci.c | 4 ++-- >>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/Platform/Marvell/Drivers/SdMmc/XenonDxe/SdMmcPciHci.c >>>> b/Platform/Marvell/Drivers/SdMmc/XenonDxe/SdMmcPciHci.c >>>> index ccbf355..0b9328b 100644 >>>> --- a/Platform/Marvell/Drivers/SdMmc/XenonDxe/SdMmcPciHci.c >>>> +++ b/Platform/Marvell/Drivers/SdMmc/XenonDxe/SdMmcPciHci.c >>>> @@ -16,6 +16,7 @@ >>>> **/ >>>> >>>> #include "SdMmcPciHcDxe.h" >>>> +#include "XenonSdhci.h" >>>> >>>> /** >>>> Dump the content of SD/MMC host controller's Capability Register. >>>> @@ -703,9 +704,8 @@ SdMmcHcClockSupply ( >>>> // >>>> // Calculate a divisor for SD clock frequency >>>> // >>>> - ASSERT (Capability.BaseClkFreq != 0); >>>> >>>> - BaseClkFreq = Capability.BaseClkFreq; >>> >>> Why is Capability.BaseClkFreq the wrong frequency to use? >>> >> >> The Capability.BaseClkFreq is UINT8 and can hold up to 0xff -> 255MHz. >> An alternative would be change this generic type to UINT16 and update >> field properly during initialization - do you prefer that? >> > > Isn't that value read from device registers?
This field in generic Capability1 register is only 8-bit wide, hence the 255MHz limitation. Xenon controller however is fed with 400MHz and it clearly cannot be obtained from there. Marcin _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
