From: Nick Sanders Date: Wed, 7 May 2014 01:52:38 +0000 (-0700) Subject: mmc: sdhci: remove mdelay in eMMC tuning X-Git-Tag: omap-for-v3.16/fixes-against-rc1~65^2~52 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=197160d52e859575ff0ad1afd674ab2a825b9f83;p=pandora-kernel.git mmc: sdhci: remove mdelay in eMMC tuning 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 Reviewed-by: Grant Grundler Reviewed-by: Doug Anderson Acked-by: Ulf Hansson Signed-off-by: Chris Ball --- Reading git-diff-tree failed