| Message ID | 1424464316-4397-1-git-send-email-dianders@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@chromium.org>
> ---
> 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@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello Doug, On 02/20/2015 09:31 PM, 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@chromium.org> > On an Exynos5250 Snow, Exynos5420 Peach Pit and Exynos5800 Peach Pi: Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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)) {
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@chromium.org> --- Changes in v2: - Also check for busy in in mci_send_cmd() drivers/mmc/host/dw_mmc.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)