>From bb0436dd5e2b3f021f8fcff2c2d25b87b48ab569 Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Sun, 24 May 2015 20:07:32 +0200 Subject: [PATCH 1/1] mmc: sunxi: fix timeout in sunxi_mmc_oclk_onoff The 250ms timeout is too short. On my system enabling the oclk takes under 50ms and disabling slightly over 100ms when idle. Under load disabling the clock can take over 350ms. This does not make mmc clock gating look like good option to have on sunxi but the system should not crash with mmc clock gating enabled nonetheless. This patch sets the timeout to 750ms and adds debug prints which show how long enabling/disabling the clock took so more data can be collected from other systems. Signed-off-by: Michal Suchanek Signed-off-by: Olliver Schinagl --- drivers/mmc/host/sunxi-mmc.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c index daa90b7..34d134c 100644 --- a/drivers/mmc/host/sunxi-mmc.c +++ b/drivers/mmc/host/sunxi-mmc.c @@ -210,6 +210,8 @@ #define SDXC_IDMAC_DES0_CES BIT(30) /* card error summary */ #define SDXC_IDMAC_DES0_OWN BIT(31) /* 1-idma owns it, 0-host owns it */ +#define SUNXI_OCLK_ONOFF_TIMEOUT 750 + struct sunxi_idma_des { u32 config; u32 buf_size; @@ -615,7 +617,7 @@ static irqreturn_t sunxi_mmc_handle_manual_stop(int irq, void *dev_id) static int sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en) { - unsigned long expire = jiffies + msecs_to_jiffies(250); + unsigned long start, end; u32 rval; int ret; @@ -629,6 +631,8 @@ static int sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en) if (oclk_en) rval |= SDXC_CARD_CLOCK_ON; + start = jiffies; + end = start + msecs_to_jiffies(SUNXI_OCLK_ONOFF_TIMEOUT); mmc_writel(host, REG_CLKCR, rval); rval = SDXC_START | SDXC_UPCLK_ONLY | SDXC_WAIT_PRE_OVER; @@ -636,15 +640,29 @@ static int sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en) do { rval = mmc_readl(host, REG_CMDR); - } while (time_before(jiffies, expire) && (rval & SDXC_START)); + } while (time_before(jiffies, end) && (rval & SDXC_START)); + end = jiffies; /* clear irq status bits set by the command */ mmc_writel(host, REG_RINTR, mmc_readl(host, REG_RINTR) & ~SDXC_SDIO_INTERRUPT); if (rval & SDXC_START) { - dev_err(mmc_dev(host->mmc), "fatal err update clk timeout\n"); + dev_err(mmc_dev(host->mmc), + "fatal err update oclk timeout. Could not %s in %ims.\n", + oclk_en ? "enable" : "disable", + jiffies_to_msecs(end - start)); return -EIO; + } else { + int msecs = jiffies_to_msecs(end - start); + const char *ing = oclk_en ? "enabling" : "disabling"; + + if ((msecs > 150) || (oclk_en && (msecs > 50))) + dev_warn(mmc_dev(host->mmc), + "%s oclk took %ims", ing, msecs); + else + dev_dbg(mmc_dev(host->mmc), + "%s oclk took %ims", ing, msecs); } return 0; -- 2.1.4