[PATCH v4 3/5] mmc: sdhci: fix SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN

From: Michał Mirosław
Date: Sun Jul 25 2021 - 05:21:04 EST


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: stable@xxxxxxxxxxxxxxx
Fixes: d1955c3a9a1d ("mmc: sdhci: add quirk SDHCI_QUIRK_CLOCK_DIV_ZERO_BROKEN")
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
---
v4: no changes
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