# \[PATCH v3 3/5\] mmc: sdhci: fix SDHCI\_QUIRK2\_CLOCK\_DIV\_ZERO\_BROKEN

- From: Michał Mirosław \<mirq-linux@rere.qmqm.pl\>
- Date: 2021-07-25 04:25:41 
- List: linux-arm-kernel
- Page: https://ratatoskr.run/linux-arm-kernel/2021/07/1456743
- Thread: https://ratatoskr.run/linux-arm-kernel/2021/07/8809939/t.md

```text
Fix returned clock rate for SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN case.
This fixes real_div value that was calculated as 1 (meaning no division)
instead of 2 with the quirk enabled.

Cc: <redacted>
Fixes: d1955c3a9a1d ("mmc: sdhci: add quirk SDHCI_QUIRK_CLOCK_DIV_ZERO_BROKEN")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
v3: updated commit message
v2: no changes
---
 drivers/mmc/host/sdhci.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 3ab60e7f936b..0993f7d0ce8e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1903,9 +1903,12 @@ u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
 
 		if (!host->clk_mul || switch_base_clk) {
 			/* Version 3.00 divisors must be a multiple of 2. */
-			if (host->max_clk <= clock)
+			if (host->max_clk <= clock) {
 				div = 1;
-			else {
+				if ((host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN)
+					&& host->max_clk <= 25000000)
+					div = 2;
+			} else {
 				for (div = 2; div < SDHCI_MAX_DIV_SPEC_300;
 				     div += 2) {
 					if ((host->max_clk / div) <= clock)
@@ -1914,9 +1917,6 @@ u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
 			}
 			real_div = div;
 			div >>= 1;
-			if ((host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN)
-				&& !div && host->max_clk <= 25000000)
-				div = 1;
 		}
 	} else {
 		/* Version 2.00 divisors must be a power of 2. */
-- 
2.30.2


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```