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Subject[PATCH] mmc: mediatek: Fixed bug where clock frequency could be set wrong
Date
From: yong mao <yong.mao@mediatek.com>

This patch can fix two issues:

Issue 1:
In previous code, div may be overflow when setting clock frequency
as f_min. We can use DIV_ROUND_UP to fix this boundary related
issue.

Issue 2:
In previous code, we can not set the correct clock frequency when
div equals 0xff.

Signed-off-by: Yong Mao <yong.mao@mediatek.com>
Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
---
drivers/mmc/host/mtk-sd.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 07f3236..3ad5228 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -591,7 +591,7 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
}
}
sdr_set_field(host->base + MSDC_CFG, MSDC_CFG_CKMOD | MSDC_CFG_CKDIV,
- (mode << 8) | (div % 0xff));
+ (mode << 8) | div);
sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_CKPDN);
while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
cpu_relax();
@@ -1692,7 +1692,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
host->src_clk_freq = clk_get_rate(host->src_clk);
/* Set host parameters to mmc */
mmc->ops = &mt_msdc_ops;
- mmc->f_min = host->src_clk_freq / (4 * 255);
+ mmc->f_min = DIV_ROUND_UP(host->src_clk_freq, 4 * 255);

mmc->caps |= MMC_CAP_ERASE | MMC_CAP_CMD23;
/* MMC core transfer sizes tunable parameters */
--
1.7.9.5
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