Hi, Doug I have two cards which are easy to get "Timeout sending command": one is ADATA uhs-1 SDR50, another is Kingston uhs-1 SDR104. After merge three patches: -- * mmc: dw_mmc: Don't start commands while busy https://patchwork.kernel.org/patch/5858221/ * mmc: dw_mmc: Make sure we only adjust the clock when power is on https://patchwork.kernel.org/patch/5858261/ * mmc: dw_mmc: Give a good reset after we give power https://patchwork.kernel.org/patch/5858281/ - Both of them can pass bind/unbind test, thank you. test script: cd /sys/bus/platform/drivers/dwmmc_rockchip for i in $(seq 1 5000); do echo "========================" $i echo ff0c0000.dwmmc > unbind sleep .5 echo ff0c0000.dwmmc > bind sleep 2 done On 2015/2/21 04:31, Doug Anderson wrote: > We've seen problems on some WiFi modules where we seem to send a CMD53 > (which requires the data lines) while the module is asserting busy. > We shouldn't do that. > > The Designware Databook says that before issuing a new data transfer > command we should check for busy, so that's what we'll do. > > We'll leverage the existing dw_mmc knowledge about whether it should > wait for the previous command to finish to know whether we should > check for busy before sending the command. This means we won't end up > incorrectly waiting for things like CMD52 (SDIO) or CMD13 (SD) which > don't use the data line. > > Note that this also has the advantage of making sure that we don't > change the clock while the card is busy, too. > > Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx> > --- > Changes in v2: > - Also check for busy in in mci_send_cmd() > > drivers/mmc/host/dw_mmc.c | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 4d2e3c2..7733c5c 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -102,6 +102,7 @@ struct idmac_desc { > > static bool dw_mci_reset(struct dw_mci *host); > static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset); > +static int dw_mci_card_busy(struct mmc_host *mmc); > > #if defined(CONFIG_DEBUG_FS) > static int dw_mci_req_show(struct seq_file *s, void *v) > @@ -335,6 +336,31 @@ static u32 dw_mci_prep_stop_abort(struct dw_mci *host, struct mmc_command *cmd) > return cmdr; > } > > +static void dw_mci_wait_while_busy(struct dw_mci *host, u32 cmd_flags) > +{ > + unsigned long timeout = jiffies + msecs_to_jiffies(500); > + > + /* > + * Databook says that before issuing a new data transfer command > + * we need to check to see if the card is busy. Data transfer commands > + * all have SDMMC_CMD_PRV_DAT_WAIT set, so we'll key off that. > + * > + * ...also allow sending for SDMMC_CMD_VOLT_SWITCH where busy is > + * expected. > + */ > + if ((cmd_flags & SDMMC_CMD_PRV_DAT_WAIT) && > + !(cmd_flags & SDMMC_CMD_VOLT_SWITCH)) { > + while (mci_readl(host, STATUS) & SDMMC_STATUS_BUSY) { > + if (time_after(jiffies, timeout)) { > + /* Command will fail; we'll pass error then */ > + dev_err(host->dev, "Busy; trying anyway\n"); > + break; > + } > + udelay(10); > + } > + } > +} > + > static void dw_mci_start_command(struct dw_mci *host, > struct mmc_command *cmd, u32 cmd_flags) > { > @@ -345,6 +371,7 @@ static void dw_mci_start_command(struct dw_mci *host, > > mci_writel(host, CMDARG, cmd->arg); > wmb(); > + dw_mci_wait_while_busy(host, cmd_flags); > > mci_writel(host, CMD, cmd_flags | SDMMC_CMD_START); > } > @@ -876,6 +903,7 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg) > > mci_writel(host, CMDARG, arg); > wmb(); > + dw_mci_wait_while_busy(host, cmd); > mci_writel(host, CMD, SDMMC_CMD_START | cmd); > > while (time_before(jiffies, timeout)) { > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
