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Patch "mmc: mediatek: Fixed bug where clock frequency could be set wrong" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Dec 18, 2017

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This is a note to let you know that I've just added the patch titled

mmc: mediatek: Fixed bug where clock frequency could be set wrong

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mmc-mediatek-fixed-bug-where-clock-frequency-could-be-set-wrong.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From foo@baz Mon Dec 18 14:47:43 CET 2017

From: yong mao <[email protected]>
Date: Sat, 4 Mar 2017 15:10:03 +0800
Subject: mmc: mediatek: Fixed bug where clock frequency could be set wrong

From: yong mao <[email protected]>

[ Upstream commit 40ceda09c8c84694c2ca6b00bcc6dc71e8e62d96 ]

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.

---
 drivers/mmc/host/mtk-sd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/mmc/host/mtk-sd.c +2 -2
@@ -570,7 +570,7 @@ static void msdc_set_mclk(struct msdc_ho
 		}
 	}
 	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();
@@ -1540,7 +1540,7 @@ static int msdc_drv_probe(struct platfor
 	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->caps |= MMC_CAP_RUNTIME_RESUME;

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/mmc-mediatek-fixed-bug-where-clock-frequency-could-be-set-wrong.patch