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mmc: msm_sdcc: Fix issue where clocks could be disabled mid transaction

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msmsdcc_enable_clocks() was incorrectly being called depending on
the state of host->clks_on. This means the busclk idle timer was never
being deleted if the clock was already on.. Bogus.

    Also fixes a possible double clk disable if the call to
del_timer_sync() in msmsdcc_disable_clocks() raced with
the busclk timer.

Signed-off-by: San Mehat <san@google.com>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
This commit is contained in:
San Mehat 2009-12-03 10:58:54 -08:00 committed by Daniel Walker
parent 6ac9ea6906
commit d0719e59f4
1 changed files with 27 additions and 34 deletions
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61
drivers/mmc/host/msm_sdcc.c
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@ -61,7 +61,7 @@ static unsigned int msmsdcc_sdioirq;
#define CMD_SPINMAX 20 #define CMD_SPINMAX 20
static inline void static inline void
msmsdcc_disable_clocks(struct msmsdcc_host *host, int deferr) msmsdcc_disable_clocks(struct msmsdcc_host *host, int deferr)
{ {
WARN_ON(!host->clks_on); WARN_ON(!host->clks_on);
@ -72,9 +72,14 @@ msmsdcc_disable_clocks(struct msmsdcc_host *host, int deferr)
mod_timer(&host->busclk_timer, jiffies + BUSCLK_TIMEOUT); mod_timer(&host->busclk_timer, jiffies + BUSCLK_TIMEOUT);
} else { } else {
del_timer_sync(&host->busclk_timer); del_timer_sync(&host->busclk_timer);
clk_disable(host->clk); /* Need to check clks_on again in case the busclk
clk_disable(host->pclk); * timer fired
host->clks_on = 0; */
if (host->clks_on) {
clk_disable(host->clk);
clk_disable(host->pclk);
host->clks_on = 0;
}
} }
} }
@ -83,21 +88,21 @@ msmsdcc_enable_clocks(struct msmsdcc_host *host)
{ {
int rc; int rc;
WARN_ON(host->clks_on);
del_timer_sync(&host->busclk_timer); del_timer_sync(&host->busclk_timer);
rc = clk_enable(host->pclk); if (!host->clks_on) {
if (rc) rc = clk_enable(host->pclk);
return rc; if (rc)
rc = clk_enable(host->clk); return rc;
if (rc) { rc = clk_enable(host->clk);
clk_disable(host->pclk); if (rc) {
return rc; clk_disable(host->pclk);
return rc;
}
udelay(1 + ((3 * USEC_PER_SEC) /
(host->clk_rate ? host->clk_rate : msmsdcc_fmin)));
host->clks_on = 1;
} }
udelay(1 + ((3 * USEC_PER_SEC) /
(host->clk_rate ? host->clk_rate : msmsdcc_fmin)));
host->clks_on = 1;
return 0; return 0;
} }
@ -180,7 +185,8 @@ msmsdcc_dma_exec_func(struct msm_dmov_cmd *cmd)
struct msmsdcc_host *host = (struct msmsdcc_host *)cmd->data; struct msmsdcc_host *host = (struct msmsdcc_host *)cmd->data;
msmsdcc_writel(host, host->cmd_timeout, MMCIDATATIMER); msmsdcc_writel(host, host->cmd_timeout, MMCIDATATIMER);
msmsdcc_writel(host, (unsigned int)host->curr.xfer_size, MMCIDATALENGTH); msmsdcc_writel(host, (unsigned int)host->curr.xfer_size,
MMCIDATALENGTH);
msmsdcc_writel(host, host->cmd_pio_irqmask, MMCIMASK1); msmsdcc_writel(host, host->cmd_pio_irqmask, MMCIMASK1);
msmsdcc_writel(host, host->cmd_datactrl, MMCIDATACTRL); msmsdcc_writel(host, host->cmd_datactrl, MMCIDATACTRL);
@ -854,13 +860,7 @@ msmsdcc_request(struct mmc_host *mmc, struct mmc_request *mrq)
return; return;
} }
/* Need to drop the host lock here in case msmsdcc_enable_clocks(host);
* the busclk wd fires
*/
spin_unlock_irqrestore(&host->lock, flags);
if (!host->clks_on)
msmsdcc_enable_clocks(host);
spin_lock_irqsave(&host->lock, flags);
host->curr.mrq = mrq; host->curr.mrq = mrq;
@ -893,11 +893,10 @@ msmsdcc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
int rc; int rc;
unsigned long flags; unsigned long flags;
if (!host->clks_on)
msmsdcc_enable_clocks(host);
spin_lock_irqsave(&host->lock, flags); spin_lock_irqsave(&host->lock, flags);
msmsdcc_enable_clocks(host);
if (ios->clock) { if (ios->clock) {
if (ios->clock != host->clk_rate) { if (ios->clock != host->clk_rate) {
rc = clk_set_rate(host->clk, ios->clock); rc = clk_set_rate(host->clk, ios->clock);
@ -1026,13 +1025,9 @@ static void
msmsdcc_busclk_expired(unsigned long _data) msmsdcc_busclk_expired(unsigned long _data)
{ {
struct msmsdcc_host *host = (struct msmsdcc_host *) _data; struct msmsdcc_host *host = (struct msmsdcc_host *) _data;
unsigned long flags;
spin_lock_irqsave(&host->lock, flags);
dev_info(mmc_dev(host->mmc), "Bus clock timer expired\n");
if (host->clks_on) if (host->clks_on)
msmsdcc_disable_clocks(host, 0); msmsdcc_disable_clocks(host, 0);
spin_unlock_irqrestore(&host->lock, flags);
} }
static int static int
@ -1324,10 +1319,8 @@ msmsdcc_suspend(struct platform_device *dev, pm_message_t state)
if (mmc->card && mmc->card->type != MMC_TYPE_SDIO) if (mmc->card && mmc->card->type != MMC_TYPE_SDIO)
rc = mmc_suspend_host(mmc, state); rc = mmc_suspend_host(mmc, state);
if (!rc) { if (!rc)
msmsdcc_writel(host, 0, MMCIMASK0); msmsdcc_writel(host, 0, MMCIMASK0);
}
if (host->clks_on) if (host->clks_on)
msmsdcc_disable_clocks(host, 0); msmsdcc_disable_clocks(host, 0);
} }