On Mon, Nov 19, 2018 at 12:03 PM Ricardo Salveti rsalveti@rsalveti.net wrote:
Hi Fabio,
On Mon, Nov 19, 2018 at 10:31 AM Fabio Estevam festevam@gmail.com wrote:
The following hang is observed on a Hummingboard 2 MicroSOM i2eX iMX6D - rev 1.3 with no eMMC populated on board:
U-Boot SPL 2018.11+gf6206f8587 (Nov 16 2018 - 00:56:34 +0000) Trying to boot from MMC1
U-Boot 2018.11+gf6206f8587 (Nov 16 2018 - 00:56:34 +0000)
CPU: Freescale i.MX6D rev1.5 996 MHz (running at 792 MHz) CPU: Extended Commercial temperature grade (-20C to 105C) at 33C Reset cause: POR Board: MX6 HummingBoard2 DRAM: 1 GiB MMC: FSL_SDHC: 0, FSL_SDHC: 1 Loading Environment from MMC... *** Warning - bad CRC, using default environment
No panel detected: default to HDMI Display: HDMI (1024x768) In: serial Out: serial Err: serial ---> hangs
which is caused by the following infinite loop inside esdhc_send_cmd_common()
while (!(esdhc_read32(®s->irqstat) & flags)) ;Instead of looping forever, provide an exit path so that a timeout error can be propagated in the case irqstat does not report any interrupts, which may happen when no eMMC is populated on board.
Reported-by: Ricardo Salveti rsalveti@rsalveti.net Signed-off-by: Fabio Estevam festevam@gmail.com
Changes since v1:
- Jump to the label out on error path (Baruch).
drivers/mmc/fsl_esdhc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 3cdfa7f..b8d0b00 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -396,6 +396,7 @@ static int esdhc_send_cmd_common(struct fsl_esdhc_priv *priv, struct mmc *mmc, uint irqstat; u32 flags = IRQSTAT_CC | IRQSTAT_CTOE; struct fsl_esdhc *regs = priv->esdhc_regs;
unsigned long start;#ifdef CONFIG_SYS_FSL_ERRATUM_ESDHC111 if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION) @@ -453,8 +454,13 @@ static int esdhc_send_cmd_common(struct fsl_esdhc_priv *priv, struct mmc *mmc, flags = IRQSTAT_BRR;
/* Wait for the command to complete */
while (!(esdhc_read32(®s->irqstat) & flags));
start = get_timer(0);while (!(esdhc_read32(®s->irqstat) & flags)) {if (get_timer(start) > 1000) {err = -ETIMEDOUT;goto out;}}This fixes the hang I was having, but adds a significant boot delay because it needs to wait until it gets the timeout (1000). Is there a better timeout value to be used here?
Looking a bit further, this ends up adding a significant boot delay because the mmc driver still tries to send another two additional commands, so it ends executing this timeout logic 3 times in total. Guess this can be improved at http://git.denx.de/?p=u-boot.git;a=blob;f=drivers/mmc/mmc.c;h=d6b9cdc99229d8... by either checking for mmc first or by simply just checking and handling the return code from mmc_send_if_cond, but this could be another patch.
Would still be nice to confirm if 1000 is the minimal timeout value to be used here.
Thanks,