Hi Stefan,
> -----Original Message----- > From: Stefan Herbrechtsmeier <stefan.herbrechtsmeier- > o...@weidmueller.com> > Sent: Monday, May 22, 2023 1:26 PM > To: Soma, Ashok Reddy <ashok.reddy.s...@amd.com>; u- > b...@lists.denx.de > Cc: Stefan Herbrechtsmeier <stefan.herbrechtsme...@weidmueller.com>; > Jaehoon Chung <jh80.ch...@samsung.com>; Simek, Michal > <michal.si...@amd.com>; Peng Fan <peng....@nxp.com>; Potthuri, Sai > Krishna <sai.krishna.potth...@amd.com> > Subject: Re: [RFC PATCH] mmc: zynq_sdhci: Dependable card detect > > Hi Ashok, > > Am 18.05.2023 um 08:20 schrieb Soma, Ashok Reddy: > > > We haven't seen any instability issue so far on ZynqMP boards and no one > reported any such issue till now. > > It isn't an instability issue. The high level at the card detect input is not > marked as stable until a short low level is detected. > > > We are already taking care of card detection stability issue with below > waiting logic. > > https://source.denx.de/u-boot/u-boot/-/blob/master/drivers/mmc/zynq_sd > > hci.c#L1161 > > This code makes problems for us. The SDHCI_CARD_STATE_STABLE signal isn't > set without a card and we see a "Sdhci card detect state not stable" message. > > > Could you please answer below questions. > > 1. is this observed in SPL only or full u-boot ? > > Both. We have enable environment support in SPL and see the "Sdhci card > detect state not stable" message after "Loading Environment from MMC..." > in SPL and "MMC: " in full U-Boot. > > > 2. is this observed in dynamic config case only ? because your patch is in > dynamic path. > > No. I have override the return value of the > zynqmp_pm_is_function_supported function and see the same error. Without > dynamic case I don't see a possibility to set the SD_CONFIG_EMMC_SEL > value. > > > 3. "On our hardware we get a "Sdhci card detect state not stable" error in > the SPL if no mmc card is present" > > Are you seeing stability issue when card is not present ? > > No, the SDHCI_CARD_STATE_STABLE signal is never set. Surprised that card card state stable signal is never set. But we cannot go with the workaround in this way. > > > can you please elaborate more about the issue. > > I have change the code to monitor the SDHCI_PRESENT_STATE signal. > Without a card at boot the SDHCI_CARD_STATE_STABLE signal is unset. > After card insert the SDHCI_CARD_PRESENT signal and the > SDHCI_CARD_STATE_STABLE signal is set after some time. After card remove > the SDHCI_CARD_STATE_STABLE signal is set and the SDHCI_CARD_PRESENT > signal is unset after some time. It doesn't matter if a physical card is > insert or > the SD_CONFIG_EMMC_SEL config is used to emulate a present card. > Without a short card present signal on the card detect logic the > SDHCI_CARD_STATE_STABLE signal isn't set. > > > 4. It is not convincing to me that you are trying to select eMMC for some > time and then switching back to SD. > > I don't find a documentation what the consequence of this config is but this > config is set based on the value of "non-removable" and setting this config > with enabled clock leads to a functional SDHCI_CARD_STATE_STABLE signal > even after unset of the config. > > Maybe the SD_CDn_CTRL register have the same result but this isn't available > via PMU. Please try any other method and lets see, but changing to eMMC mode and back to SDHC is NOT acceptable according to me. Thanks, Ashok > > Regards > Stefan > > >> -----Original Message----- > >> From: U-Boot <u-boot-boun...@lists.denx.de> On Behalf Of Stefan > >> Herbrechtsmeier > >> Sent: Tuesday, May 16, 2023 7:51 PM > >> To: u-boot@lists.denx.de > >> Cc: Stefan Herbrechtsmeier <stefan.herbrechtsme...@weidmueller.com>; > >> Jaehoon Chung <jh80.ch...@samsung.com>; Simek, Michal > >> <michal.si...@amd.com>; Peng Fan <peng....@nxp.com> > >> Subject: [RFC PATCH] mmc: zynq_sdhci: Dependable card detect > >> > >> CAUTION: This message has originated from an External Source. Please > >> use proper judgment and caution when opening attachments, clicking > >> links, or responding to this email. > >> > >> > >> From: Stefan Herbrechtsmeier > <stefan.herbrechtsme...@weidmueller.com> > >> > >> The card detect logic needs a short card present signal to work > dependable. > >> Without a present card the SDHCI_CARD_STATE_STABLE signal is not set > >> dependable after a reset. Use the internal fixed card present signal > >> to initiate the card detect logic. > >> > >> Signed-off-by: Stefan Herbrechtsmeier > >> <stefan.herbrechtsme...@weidmueller.com> > >> > >> --- > >> On our hardware we get a "Sdhci card detect state not stable" error > >> in the SPL if no mmc card is present. It is unclear if this patch is > >> the correct solution, but a short card inserts or a fixed card > >> present signal leads to a SDHCI_CARD_STATE_STABLE signal with and > without card. > >> > >> drivers/mmc/zynq_sdhci.c | 20 ++++++++++++++++++++ > >> 1 file changed, 20 insertions(+) > >> > >> diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c > >> index > >> e44868aaec..a88feeb367 100644 > >> --- a/drivers/mmc/zynq_sdhci.c > >> +++ b/drivers/mmc/zynq_sdhci.c > >> @@ -1075,6 +1075,26 @@ static int > >> sdhci_zynqmp_set_dynamic_config(struct arasan_sdhci_priv *priv, > >> return ret; > >> } > >> > >> + /* The card detect logic needs a short card present signal to work > >> + * dependable. Without a present card the > SDHCI_CARD_STATE_STABLE > >> + * signal is not set dependable after a reset. Use the internal > >> + * fixed card present signal to initiate the card detect logic. > >> + */ > >> + if (!dev_read_bool(dev, "non-removable")) { > >> + ret = zynqmp_pm_set_sd_config(priv->node_id, > >> SD_CONFIG_EMMC_SEL, > >> + 1); > >> + if (ret) { > >> + dev_err(dev, "SD_CONFIG_EMMC_SEL failed\n"); > >> + return ret; > >> + } > >> + ret = zynqmp_pm_set_sd_config(priv->node_id, > >> SD_CONFIG_EMMC_SEL, > >> + 0); > >> + if (ret) { > >> + dev_err(dev, "SD_CONFIG_EMMC_SEL failed\n"); > >> + return ret; > >> + } > >> + } > >> + > >> return 0; > >> } > >> #endif > >> -- > >> 2.30.2
