Hi Pantelis,
On 05.11.15 20:58, Gregory CLEMENT wrote:
Timing issue occurs on eMMC not only when modifying the frequency but also for all the switch command(CMD6). According to the MMC spec waiting 8 clocks after a switch command would be the thing to do.
This patch allows fixing CPU hang observed when trying to changing the bus width on a eMMC on SAMA5D4.
Signed-off-by: Gregory CLEMENT gregory.clement@free-electrons.com Tested-by: Marek Vasut marex@denx.de # on DENX MA5D4EV
this patch [1] is delegated to you on patchwork ... will you take it?
Andreas
[1] http://patchwork.ozlabs.org/patch/540686/
drivers/mmc/gen_atmel_mci.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/gen_atmel_mci.c b/drivers/mmc/gen_atmel_mci.c index da870c6..f090b27 100644 --- a/drivers/mmc/gen_atmel_mci.c +++ b/drivers/mmc/gen_atmel_mci.c @@ -36,6 +36,7 @@ struct atmel_mci_priv { struct mmc_config cfg; struct atmel_mci *mci; unsigned int initialized:1;
- unsigned int curr_clk;
};
/* Read Atmel MCI IP version */ @@ -91,7 +92,10 @@ static void mci_set_mode(struct mmc *mmc, u32 hz, u32 blklen)
}}
if (version >= 0x500)
priv->curr_clk = bus_hz / (clkdiv * 2 + clkodd + 2);else
priv->curr_clk = (bus_hz / (clkdiv + 1)) / 2;blklen &= 0xfffc;
mr = MMCI_BF(CLKDIV, clkdiv);
@@ -118,8 +122,6 @@ static void mci_set_mode(struct mmc *mmc, u32 hz, u32 blklen) if (mmc->card_caps & mmc->cfg->host_caps & MMC_MODE_HS) writel(MMCI_BIT(HSMODE), &mci->cfg);
- udelay(50);
- priv->initialized = 1;
}
@@ -323,6 +325,13 @@ mci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data) } }
- /*
* After the switch command, wait for 8 clocks before the next* command*/- if (cmd->cmdidx == MMC_CMD_SWITCH)
udelay(8*1000000/ priv->curr_clk); /* 8 clk in us */- return 0;
}