On 29/01/15 11:00, Adrian Hunter wrote: > Hi > > Here is V2 of some patches to move re-tuning support > out of sdhci and into the core, and add support for HS400 > re-tuning. > > Currently sdhci does re-tuning transparently by > calling sdhci_execute_tuning() from its ->request() > function. > > The problem with HS400 re-tuning is that it must be > done in HS200 mode. That means using switch commands > and making ios changes. That means it potentially > conflicts with other command sequences. The new > re-tuning support accomodates that, however it is > not strictly necessary because HS400 re-tuning > should only be needed after runtime suspend when > there would not be a conflict. > > Nevertheless, this approach has more structure > and potentially more flexibility. > > Changes in V2: > > Added support to the block driver for re-tuning > and retrying after a CRC error. The host driver > is left to decide when an error indicates re-tuning > is needed. The block driver will retry a data request > once if re-tuning is flagged as needed. > > SDIO drivers need not be aware of re-tuning because > retrying will anyway cause re-tuning when re-tuning > is flagged as needed. Nevertheless SDIO drivers could > use the need_retune flag to instigate a retry when > otherwise they might not have.
Ulf, Arend, is this OK? -- 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
