From mboxrd@z Thu Jan 1 00:00:00 1970 From: 21cnbao@gmail.com (Barry Song) Date: Mon, 23 Dec 2013 21:50:08 +0800 Subject: [PATCH] mmc: sdhci: use time_after to replace mdelay-loop for timeout Message-ID: <1387806608-3467-1-git-send-email-21cnbao@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Barry Song 1ms busy-loop might be wasted when the condition "if(sdhci_readl(host, SDHCI_PRESENT_STATE) & mask)" becomes false just after the if(). here we use time_after which will have no redundant busy-wait loop. Signed-off-by: Barry Song Cc: Bin Shi --- drivers/mmc/host/sdhci.c | 10 ++++------ 1 files changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index aac92bd..52f5289 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1036,9 +1036,6 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd) WARN_ON(host->cmd); - /* Wait max 10 ms */ - timeout = 10; - mask = SDHCI_CMD_INHIBIT; if ((cmd->data != NULL) || (cmd->flags & MMC_RSP_BUSY)) mask |= SDHCI_DATA_INHIBIT; @@ -1048,8 +1045,11 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd) if (host->mrq->data && (cmd == host->mrq->data->stop)) mask &= ~SDHCI_DATA_INHIBIT; + /* Wait max 10 ms */ + timeout = jiffies + msecs_to_jiffies(10); + while (sdhci_readl(host, SDHCI_PRESENT_STATE) & mask) { - if (timeout == 0) { + if (time_after(jiffies, timeout)) { pr_err("%s: Controller never released " "inhibit bit(s).\n", mmc_hostname(host->mmc)); sdhci_dumpregs(host); @@ -1057,8 +1057,6 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd) tasklet_schedule(&host->finish_tasklet); return; } - timeout--; - mdelay(1); } mod_timer(&host->timer, jiffies + 10 * HZ); -- 1.7.5.4