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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:
Nick Sanders <nsanders@chromium.org> Reviewed-by:
Grant Grundler <grundler@chromium.org> Reviewed-by:
Doug Anderson <dianders@chromium.org> Acked-by:
Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by:
Chris Ball <chris@printf.net>
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