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Message-Id: <20200319123913.982249573@linuxfoundation.org>
Date: Thu, 19 Mar 2020 14:04:17 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Faiz Abbas <faiz_abbas@...com>,
Ulf Hansson <ulf.hansson@...aro.org>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 35/48] mmc: sdhci-omap: Fix Tuning procedure for temperatures < -20C
From: Faiz Abbas <faiz_abbas@...com>
[ Upstream commit feb40824d78eac5e48f56498dca941754dff33d7 ]
According to the App note[1] detailing the tuning algorithm, for
temperatures < -20C, the initial tuning value should be min(largest value
in LPW - 24, ceil(13/16 ratio of LPW)). The largest value in LPW is
(max_window + 4 * (max_len - 1)) and not (max_window + 4 * max_len) itself.
Fix this implementation.
[1] http://www.ti.com/lit/an/spraca9b/spraca9b.pdf
Fixes: 961de0a856e3 ("mmc: sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures (i929)")
Cc: stable@...r.kernel.org
Signed-off-by: Faiz Abbas <faiz_abbas@...com>
Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/mmc/host/sdhci-omap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 833e13cabd2a8..05ade7a2dd243 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -387,7 +387,7 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
* on temperature
*/
if (temperature < -20000)
- phase_delay = min(max_window + 4 * max_len - 24,
+ phase_delay = min(max_window + 4 * (max_len - 1) - 24,
max_window +
DIV_ROUND_UP(13 * max_len, 16) * 4);
else if (temperature < 20000)
--
2.20.1
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