On Tuesday, August 29, 2012, Jaehoon Chung <[email protected]> wrote: > On 08/29/2012 10:21 AM, Seungwon Jeon wrote: > > On Tuesday, August 28, 2012, Jaehoon Chung <[email protected]> wrote: > >> synopsys spec is mentioned. (7.1 Software/Hardware Restrictions) > >> "Before disabling clock, ensure that card is not busy due to any previous > >> data command." > >> > >> At specific board, i found the problem that didn't inform ciu. > >> (It didn't produce always.) > >> At that time, i checked the status register whether card is busy or not. > >> (Start bit of CMD register is cleared, but card is busy.) > >> Current code didn't check the card status. Just check whether the > >> start-bit cleared. > >> host regard that command is completed, will send the next command. > >> But next command didn't issue because Card is busy. > >> This patch can prevent this situation. > >> > >> Signed-off-by: Jaehoon Chung <[email protected]> > >> --- > >> drivers/mmc/host/dw_mmc.c | 27 +++++++++++++++++++++------ > >> drivers/mmc/host/dw_mmc.h | 1 + > >> 2 files changed, 22 insertions(+), 6 deletions(-) > >> > >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > >> index 36f98c0..e30d3ed 100644 > >> --- a/drivers/mmc/host/dw_mmc.c > >> +++ b/drivers/mmc/host/dw_mmc.c > >> @@ -623,6 +623,24 @@ static void mci_send_cmd(struct dw_mci_slot *slot, > >> u32 cmd, u32 arg) > >> cmd, arg, cmd_status); > >> } > >> > >> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot) > >> +{ > >> + struct dw_mci *host = slot->host; > >> + unsigned long timeout = jiffies + msecs_to_jiffies(10); > > 10ms is from test? > It's tested...it's not exactly value..but never spent the time. > > > >> + u32 ctrl, status; > >> + > >> + do { > >> + status = mci_readl(host, STATUS); > >> + if (!(status & SDMMC_DATA_BUSY)) > >> + break; > >> + ctrl = mci_readl(host, CTRL); > >> + ctrl |= SDMMC_CTRL_RESET; > >> + mci_writel(host, CTRL, ctrl); > >> + } while (time_before(jiffies, timeout)); > >> + > >> + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); > >> +} > >> + > >> static void dw_mci_setup_bus(struct dw_mci_slot *slot) > >> { > >> struct dw_mci *host = slot->host; > >> @@ -650,15 +668,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot > >> *slot) > > According to your quotation of manual("Before disabling clock, ...), > > Place of dw_mci_inform_ciu is proper here? > manual is mentioned "before the disabling clock". but i think no problem > before send the command. > > > > dw_mci_inform_ciu(slot); > > > > /* disable clock */ > > mci_writel(host, CLKENA, 0); > > mci_writel(host, CLKSRC, 0); > > > >> mci_writel(host, CLKSRC, 0); > >> > >> /* inform CIU */ > >> - mci_send_cmd(slot, > >> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); > >> + dw_mci_inform_ciu(slot); > >> > >> /* set clock to desired speed */ > >> mci_writel(host, CLKDIV, div); > >> > >> /* inform CIU */ > >> - mci_send_cmd(slot, > >> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); > >> + dw_mci_inform_ciu(slot); > > And then, since start to change clock sequence, there is no need to check > > busy-status. > > Just need to update clock with origin code. > Right, didn't check the busy-status. but there is also no reason that didn't > need to check busy-status. Ok, I mentioned no check busy-status because host doesn't send command to card in the middle of host's clock update. If you have a opinion, please let me know.
Thanks, Seungwon Jeon > >> > >> /* enable clock; only low power if no SDIO */ > >> clk_en_a = SDMMC_CLKEN_ENABLE << slot->id; > >> @@ -667,8 +683,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot) > >> mci_writel(host, CLKENA, clk_en_a); > >> > >> /* inform CIU */ > >> - mci_send_cmd(slot, > >> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); > >> + dw_mci_inform_ciu(slot); > > Same here. > > > > Thanks, > > Seungwon Jeon > >> > >> host->current_speed = slot->clock; > >> } > >> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h > >> index 15c27e1..b6a1a78 100644 > >> --- a/drivers/mmc/host/dw_mmc.h > >> +++ b/drivers/mmc/host/dw_mmc.h > >> @@ -127,6 +127,7 @@ > >> #define SDMMC_CMD_INDX(n) ((n) & 0x1F) > >> /* Status register defines */ > >> #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF) > >> +#define SDMMC_DATA_BUSY BIT(9) > >> /* Internal DMAC interrupt defines */ > >> #define SDMMC_IDMAC_INT_AI BIT(9) > >> #define SDMMC_IDMAC_INT_NI BIT(8) > >> -- > >> 1.7.4.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > > the body of a message to [email protected] > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
