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* [PATCH] mmc: dw_mmc-exynos: fixed wrong sample-clock selection
@ 2014-09-15 10:26 Jaehoon Chung
  2014-09-16 22:27 ` Alim Akhtar
  0 siblings, 1 reply; 5+ messages in thread
From: Jaehoon Chung @ 2014-09-15 10:26 UTC (permalink / raw)
  To: linux-mmc; +Cc: Chris Ball, Ulf Hansson, tgih.jun, Jaehoon Chung

Almost all case is selected to 0.
(It's not correct sample-clock value.)
Since it set to wrong value, HS200 mode don't work fine.
If we want to select the correct value, it has to check from 1 to 7.(skip 0)

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 drivers/mmc/host/dw_mmc-exynos.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 0fbc53a..5294035 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -25,6 +25,7 @@
 #define NUM_PINS(x)			(x + 2)
 
 #define SDMMC_CLKSEL			0x09C
+#define SDMMC_CLKSEL_CCLK_SAMPLE_MASK	0x7
 #define SDMMC_CLKSEL_CCLK_SAMPLE(x)	(((x) & 7) << 0)
 #define SDMMC_CLKSEL_CCLK_DRIVE(x)	(((x) & 7) << 16)
 #define SDMMC_CLKSEL_CCLK_DIVIDER(x)	(((x) & 7) << 24)
@@ -330,6 +331,12 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode,
 	if (!blk_test)
 		return -ENOMEM;
 
+	/*
+	 * In order to check all selclk_sample clock,
+	 * it needs to reset to 0.
+	 */
+	dw_mci_exynos_set_clksmpl(host, 0);
+
 	start_smpl = dw_mci_exynos_get_clksmpl(host);
 
 	do {
@@ -372,7 +379,7 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode,
 				"Tuning error: cmd.error:%d, data.error:%d\n",
 				cmd.error, data.error);
 		}
-	} while (start_smpl != smpl);
+	} while (start_smpl < SDMMC_CLKSEL_CCLK_SAMPLE_MASK);
 
 	found = dw_mci_exynos_get_best_clksmpl(candiates);
 	if (found >= 0)
-- 
1.7.9.5


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2014-09-18 10:50 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-09-15 10:26 [PATCH] mmc: dw_mmc-exynos: fixed wrong sample-clock selection Jaehoon Chung
2014-09-16 22:27 ` Alim Akhtar
2014-09-17  2:36   ` Jaehoon Chung
2014-09-17 12:49     ` Alim Akhtar
2014-09-18 10:50       ` Jaehoon Chung

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