2017-03-04 07:17:55

by Yong Mao

Subject: [PATCH v2] mmc: mediatek: Fixed bug where clock frequency could be set wrong

yong mao (1):
mmc: mediatek: Fixed bug where clock frequency could be set wrong

drivers/mmc/host/mtk-sd.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--
1.8.1.1.dirty

2017-03-04 07:17:56

by Yong Mao

Subject: [PATCH] mmc: mediatek: Fixed bug where clock frequency could be set wrong

From: yong mao <[email protected]>

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 <[email protected]>
Signed-off-by: Chaotian Jing <[email protected]>
---
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

2017-03-06 07:16:08

by Daniel Kurtz

Subject: Re: [PATCH] mmc: mediatek: Fixed bug where clock frequency could be set wrong

Hi Yong,

On Sat, Mar 4, 2017 at 3:10 PM, Yong Mao <[email protected]> wrote:
> From: yong mao <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Chaotian Jing <[email protected]>

Reviewed-by: Daniel Kurtz <[email protected]>

> ---
> 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
>

2017-03-16 14:46:02

by Ulf Hansson

Subject: Re: [PATCH] mmc: mediatek: Fixed bug where clock frequency could be set wrong

On 4 March 2017 at 08:10, Yong Mao <[email protected]> wrote:
> From: yong mao <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Chaotian Jing <[email protected]>
> ---
> 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
>

Thanks, applied for fixes!

Kind regards
Uffe