Hi Marek, On jeu., nov. 05 2015, Marek Vasut <[email protected]> wrote:
> On Thursday, November 05, 2015 at 08:58:30 PM, 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 <[email protected]> >> Tested-by: Marek Vasut <[email protected]> # on DENX MA5D4EV >> --- >> 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 */ > > Is there a chance that curr_clk will be inited to zero and this would > be called? curr_clk is set in the mci_set_mode function which is called from mci_init which is called by the mmc core function mmc_start_init before any use of a command and especially of mci_send_cmd(). So we are safe. > I guess the easy fix is to init curr_clk to 1 in the probe() call. Sorry that > I > didn't mention this earlier. > > Otherwise, > > Acked-by: Marek Vasut <[email protected]> Thanks, Gregory > >> + >> return 0; >> } > > Best regards, > Marek Vasut -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
