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[0/2] mmc: bcm2835_sdhost: use fallback clock rate

Message ID 20210914181919.584951-1-vfazio@xes-inc.com
Headers show
Series mmc: bcm2835_sdhost: use fallback clock rate | expand

Message

Vincent Fazio Sept. 14, 2021, 6:19 p.m. UTC 
Recent raspberry pi firmware has modified the behavior of GET_CLOCK_RATE
to return zero (0) when there is no previous call to SET_CLOCK_RATE.

This affects callers of bcm2835_get_mmc_clock and can lead to degraded
MMC performance.

Now, return the result of GET_MAX_CLOCK_RATE if GET_CLOCK_RATE is zero.

Additionally, let the firmware manage SDCDIV when possible.


Vincent Fazio (2):
  arm: rpi: fallback to max clock rate for MMC clock
  mmc: bcm2835-host: let firmware manage the clock divisor

 arch/arm/mach-bcm283x/include/mach/mbox.h | 18 ++++++++
 arch/arm/mach-bcm283x/include/mach/msg.h  | 10 +++++
 arch/arm/mach-bcm283x/msg.c               | 47 +++++++++++++++++++-
 drivers/mmc/bcm2835_sdhost.c              | 53 ++++++++++++++---------
 4 files changed, 106 insertions(+), 22 deletions(-)