summaryrefslogtreecommitdiffstats
path: root/drivers/mmc
diff options
context:
space:
mode:
authorNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>2018-07-24 16:51:38 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2018-08-01 12:02:03 +0200
commit5c99826b27d0afd4c05c2013385b17037f579cf9 (patch)
tree7af6f54b848c611fea82e6417d196f72bda932f0 /drivers/mmc
parenta8f399f624e1ae902828ad788f3601ff7b3e0eed (diff)
downloadlinux-5c99826b27d0afd4c05c2013385b17037f579cf9.tar.bz2
mmc: renesas_sdhi: Fix sampling clock position selecting
When tuning each tap is issued CMD19 twice and the result of both runs recorded in host->taps. If the result is different between the two runs the wrong sampling clock position was selected. Fix this by merging the two runs and only keep the result for each tap if it was good in both sets. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/renesas_sdhi_core.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 384ae6cfa289..777e32b0e410 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -385,6 +385,18 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host)
sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
/*
+ * When tuning CMD19 is issued twice for each tap, merge the
+ * result requiring the tap to be good in both runs before
+ * considering it for tuning selection.
+ */
+ for (i = 0; i < host->tap_num * 2; i++) {
+ int offset = host->tap_num * (i < host->tap_num ? 1 : -1);
+
+ if (!test_bit(i, host->taps))
+ clear_bit(i + offset, host->taps);
+ }
+
+ /*
* Find the longest consecutive run of successful probes. If that
* is more than SH_MOBILE_SDHI_MAX_TAP probes long then use the
* center index as the tap.