From 53e60650f74ed42957bea947ea791b6dea215b01 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 9 Nov 2016 19:40:29 +0100 Subject: [PATCH] mmc: core: Allow CMD13 polling when switching to HS mode for mmc In cases when the mmc host doesn't support HW busy detection, polling for a card being busy by using CMD13 is beneficial. That is because, instead of waiting a fixed amount of time, 500ms or the generic CMD6 time from EXT_CSD, we find out a lot sooner when the card stops signaling busy. This leads to a significant decreased total initialization time for the mmc card. However, to allow polling with CMD13 during a bus timing change operation, such as switching to HS mode, we first need to update the mmc host's bus timing before starting to poll. Deal with that, simply by providing MMC_TIMING_MMC_HS as the timing parameter to __mmc_switch() from mmc_select_hs(). By telling __mmc_switch() to allow polling with CMD13, also makes it validate the CMD6 status, thus we can remove the corresponding checks. When switching to HS400ES, the mmc_select_hs() function is called in one of the intermediate steps. To still prevent CMD13 polling for HS400ES, let's call the __mmc_switch() function in this path as it enables us to keep using the existing method. Signed-off-by: Ulf Hansson Tested-by: Linus Walleij Acked-by: Adrian Hunter --- drivers/mmc/core/mmc.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index cb1cf4e5d916..15dd51cfd083 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1012,13 +1012,8 @@ static int mmc_select_hs(struct mmc_card *card) err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS, - card->ext_csd.generic_cmd6_time, 0, - true, false, true); - if (!err) { - mmc_set_timing(card->host, MMC_TIMING_MMC_HS); - err = mmc_switch_status(card); - } - + card->ext_csd.generic_cmd6_time, MMC_TIMING_MMC_HS, + true, true, true); if (err) pr_warn("%s: switch to high-speed failed, err:%d\n", mmc_hostname(card->host), err); @@ -1268,16 +1263,23 @@ static int mmc_select_hs400es(struct mmc_card *card) goto out_err; /* Switch card to HS mode */ - err = mmc_select_hs(card); - if (err) + err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS, + card->ext_csd.generic_cmd6_time, 0, + true, false, true); + if (err) { + pr_err("%s: switch to hs for hs400es failed, err:%d\n", + mmc_hostname(host), err); goto out_err; + } - mmc_set_clock(host, card->ext_csd.hs_max_dtr); - + mmc_set_timing(host, MMC_TIMING_MMC_HS); err = mmc_switch_status(card); if (err) goto out_err; + mmc_set_clock(host, card->ext_csd.hs_max_dtr); + /* Switch card to DDR with strobe bit */ val = EXT_CSD_DDR_BUS_WIDTH_8 | EXT_CSD_BUS_WIDTH_STROBE; err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, -- 2.20.1