1. 22 May, 2014 13 commits
  2. 14 May, 2014 1 commit
    • Nick Sanders's avatar
      mmc: sdhci: remove mdelay in eMMC tuning · 197160d5
      Nick Sanders authored
      This patch removes an unneccesary 1ms mdelay in the HS200 tuning
      loop, called 40 times per retuning. Currently this causes a latency
      of >40ms on any emmc accesses triggering wake from runtime PM,
      which can occur for a significant portion of reads on a mostly idle system.
      
      The delay is left in place for SD Cards, which use
      MMC_SEND_TUNING_BLOCK rather than MMC_SEND_TUNING_BLOCK_HS200.
      I'm not able to find evidence that this is required for SD in the
      specs I have access to, however this delay has been present from
      initial checkin for SD so I have preserved the original behavior for
      compatibility.
      
      This has been verified to fix observed glitching on local audio
      playback and recording on apps with inbuilt assumptions on storage
      latency.
      Signed-off-by: default avatarNick Sanders <nsanders@chromium.org>
      Reviewed-by: default avatarGrant Grundler <grundler@chromium.org>
      Reviewed-by: default avatarDoug Anderson <dianders@chromium.org>
      Acked-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarChris Ball <chris@printf.net>
      197160d5
  3. 12 May, 2014 26 commits