[PATCH 2/6] mmc: sdhci-s3c: Cache bus clock rates
Tomasz Figa
tomasz.figa at gmail.com
Sat Jan 11 16:39:02 EST 2014
To fix scheduling while atomic happening in sdhci_s3c_set_clock() caused
by calling clk_get_rate() that might sleep, this patch modifies the
driver to cache rates of all bus clocks at probe time and then only use
those cache values.
Signed-off-by: Tomasz Figa <tomasz.figa at gmail.com>
---
drivers/mmc/host/sdhci-s3c.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index 52770d5..9b78391 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -57,6 +57,7 @@ struct sdhci_s3c {
struct clk *clk_io;
struct clk *clk_bus[MAX_BUS_CLK];
+ unsigned long clk_rates[MAX_BUS_CLK];
};
/**
@@ -158,7 +159,7 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
return wanted - rate;
}
- rate = clk_get_rate(clksrc);
+ rate = ourhost->clk_rates[src];
for (shift = 0; shift < 8; ++shift) {
if ((rate >> shift) <= wanted)
@@ -215,7 +216,7 @@ static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
ourhost->cur_clk = best_src;
- host->max_clk = clk_get_rate(clk);
+ host->max_clk = ourhost->clk_rates[best_src];
ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
@@ -583,8 +584,10 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
*/
sc->cur_clk = ptr;
+ sc->clk_rates[ptr] = clk_get_rate(sc->clk_bus[ptr]);
+
dev_info(dev, "clock source %d: %s (%ld Hz)\n",
- ptr, name, clk_get_rate(clk));
+ ptr, name, sc->clk_rates[ptr]);
}
if (clks == 0) {
--
1.8.5.2
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