On 29/10/2010 21:18, Linus Walleij wrote: > This patch modifies the MMC core code to optionally call the > set_ios() operation on the driver with the clock frequency set > to 0 (gate) after a grace period of at least 8 MCLK cycles, then > restore it (ungate) before any new request. This gives > the driver the option to shut down the MCI clock to the MMC/SD > card when the clock frequency is 0, i.e. the core has stated > that the MCI clock does not need to be generated.
With SDIO cards, 1 bit mode needs to be set on the controller otherwise many controllers cannot detect card interrupts. Also some v2.00 SDIO cards in 4-bit mode will not generate card interrupts unless they are clocked (the spec v2.00 doesn't require them to be able to but v3.00 does). I would suggest a white list of v2.00 cards that can generate interrupts asynchronousy. David -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
