From: Stefan Wahren <stefan.wahren@i2se.com> To: Rob Herring <robh+dt@kernel.org>, Nicolas Saenz Julienne <nsaenz@kernel.org>, Florian Fainelli <f.fainelli@gmail.com>, Adrian Hunter <adrian.hunter@intel.com>, Ulf Hansson <ulf.hansson@linaro.org> Cc: Ray Jui <rjui@broadcom.com>, Scott Branden <sbranden@broadcom.com>, bcm-kernel-feedback-list@broadcom.com, Maxime Ripard <maxime@cerno.tech>, iivanov@suse.de, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Stefan Wahren <stefan.wahren@i2se.com> Subject: [PATCH V2 04/10] mmc: sdhci-iproc: Cap min clock frequency on BCM2711 Date: Sat, 7 Aug 2021 13:06:35 +0200 [thread overview] Message-ID: <1628334401-6577-5-git-send-email-stefan.wahren@i2se.com> (raw) In-Reply-To: <1628334401-6577-1-git-send-email-stefan.wahren@i2se.com> From: Nicolas Saenz Julienne <nsaenz@kernel.org> There is a known bug on BCM2711's SDHCI core integration where the controller will hang when the difference between the core clock and the bus clock is too great. Specifically this can be reproduced under the following conditions: - No SD card plugged in, polling thread is running, probing cards at 100 kHz. - BCM2711's core clock configured at 500MHz or more. So set 200 kHz as the minimum clock frequency available for that board. For more information on the issue see this: https://lore.kernel.org/linux-mmc/20210322185816.27582-1-nsaenz@kernel.org/T/#m11f2783a09b581da6b8a15f302625b43a6ecdeca Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711") Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> --- drivers/mmc/host/sdhci-iproc.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/mmc/host/sdhci-iproc.c b/drivers/mmc/host/sdhci-iproc.c index cce390f..032bf85 100644 --- a/drivers/mmc/host/sdhci-iproc.c +++ b/drivers/mmc/host/sdhci-iproc.c @@ -173,6 +173,23 @@ static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host) return pltfm_host->clock; } +/* + * There is a known bug on BCM2711's SDHCI core integration where the + * controller will hang when the difference between the core clock and the bus + * clock is too great. Specifically this can be reproduced under the following + * conditions: + * + * - No SD card plugged in, polling thread is running, probing cards at + * 100 kHz. + * - BCM2711's core clock configured at 500MHz or more + * + * So we set 200kHz as the minimum clock frequency available for that SoC. + */ +static unsigned int sdhci_iproc_bcm2711_get_min_clock(struct sdhci_host *host) +{ + return 200000; +} + static const struct sdhci_ops sdhci_iproc_ops = { .set_clock = sdhci_set_clock, .get_max_clock = sdhci_iproc_get_max_clock, @@ -271,6 +288,7 @@ static const struct sdhci_ops sdhci_iproc_bcm2711_ops = { .set_clock = sdhci_set_clock, .set_power = sdhci_set_power_and_bus_voltage, .get_max_clock = sdhci_iproc_get_max_clock, + .get_min_clock = sdhci_iproc_bcm2711_get_min_clock, .set_bus_width = sdhci_set_bus_width, .reset = sdhci_reset, .set_uhs_signaling = sdhci_set_uhs_signaling, -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Stefan Wahren <stefan.wahren@i2se.com> To: Rob Herring <robh+dt@kernel.org>, Nicolas Saenz Julienne <nsaenz@kernel.org>, Florian Fainelli <f.fainelli@gmail.com>, Adrian Hunter <adrian.hunter@intel.com>, Ulf Hansson <ulf.hansson@linaro.org> Cc: Ray Jui <rjui@broadcom.com>, Scott Branden <sbranden@broadcom.com>, bcm-kernel-feedback-list@broadcom.com, Maxime Ripard <maxime@cerno.tech>, iivanov@suse.de, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Stefan Wahren <stefan.wahren@i2se.com> Subject: [PATCH V2 04/10] mmc: sdhci-iproc: Cap min clock frequency on BCM2711 Date: Sat, 7 Aug 2021 13:06:35 +0200 [thread overview] Message-ID: <1628334401-6577-5-git-send-email-stefan.wahren@i2se.com> (raw) In-Reply-To: <1628334401-6577-1-git-send-email-stefan.wahren@i2se.com> From: Nicolas Saenz Julienne <nsaenz@kernel.org> There is a known bug on BCM2711's SDHCI core integration where the controller will hang when the difference between the core clock and the bus clock is too great. Specifically this can be reproduced under the following conditions: - No SD card plugged in, polling thread is running, probing cards at 100 kHz. - BCM2711's core clock configured at 500MHz or more. So set 200 kHz as the minimum clock frequency available for that board. For more information on the issue see this: https://lore.kernel.org/linux-mmc/20210322185816.27582-1-nsaenz@kernel.org/T/#m11f2783a09b581da6b8a15f302625b43a6ecdeca Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711") Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> --- drivers/mmc/host/sdhci-iproc.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/mmc/host/sdhci-iproc.c b/drivers/mmc/host/sdhci-iproc.c index cce390f..032bf85 100644 --- a/drivers/mmc/host/sdhci-iproc.c +++ b/drivers/mmc/host/sdhci-iproc.c @@ -173,6 +173,23 @@ static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host) return pltfm_host->clock; } +/* + * There is a known bug on BCM2711's SDHCI core integration where the + * controller will hang when the difference between the core clock and the bus + * clock is too great. Specifically this can be reproduced under the following + * conditions: + * + * - No SD card plugged in, polling thread is running, probing cards at + * 100 kHz. + * - BCM2711's core clock configured at 500MHz or more + * + * So we set 200kHz as the minimum clock frequency available for that SoC. + */ +static unsigned int sdhci_iproc_bcm2711_get_min_clock(struct sdhci_host *host) +{ + return 200000; +} + static const struct sdhci_ops sdhci_iproc_ops = { .set_clock = sdhci_set_clock, .get_max_clock = sdhci_iproc_get_max_clock, @@ -271,6 +288,7 @@ static const struct sdhci_ops sdhci_iproc_bcm2711_ops = { .set_clock = sdhci_set_clock, .set_power = sdhci_set_power_and_bus_voltage, .get_max_clock = sdhci_iproc_get_max_clock, + .get_min_clock = sdhci_iproc_bcm2711_get_min_clock, .set_bus_width = sdhci_set_bus_width, .reset = sdhci_reset, .set_uhs_signaling = sdhci_set_uhs_signaling, -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-08-07 11:07 UTC|newest] Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-07 11:06 [PATCH V2 00/10] ARM: dts: Add Raspberry Pi CM4 & CM4 IO Board support Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-07 11:06 ` [PATCH V2 01/10] ARM: dts: bcm2711: fix MDIO #address- and #size-cells Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-07 11:06 ` [PATCH V2 02/10] ARM: dts: bcm2711-rpi-4-b: fix sd_io_1v8_reg regulator states Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-07 11:06 ` [PATCH V2 03/10] dt-bindings: display: bcm2835: add optional property power-domains Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren [this message] 2021-08-07 11:06 ` [PATCH V2 04/10] mmc: sdhci-iproc: Cap min clock frequency on BCM2711 Stefan Wahren 2021-08-16 13:59 ` Ulf Hansson 2021-08-16 13:59 ` Ulf Hansson 2021-08-07 11:06 ` [PATCH V2 05/10] mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN " Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-16 13:59 ` Ulf Hansson 2021-08-16 13:59 ` Ulf Hansson 2021-08-26 6:36 ` Jeremy Linton 2021-08-26 6:36 ` Jeremy Linton 2021-08-26 9:22 ` Ulf Hansson 2021-08-26 9:22 ` Ulf Hansson 2021-08-26 11:18 ` Stefan Wahren 2021-08-26 11:18 ` Stefan Wahren 2021-08-27 14:44 ` Ulf Hansson 2021-08-27 14:44 ` Ulf Hansson 2021-08-07 11:06 ` [PATCH V2 06/10] ARM: dts: bcm283x-rpi: Move Wifi/BT into separate dtsi Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-07 11:06 ` [PATCH V2 07/10] dt-bindings: arm: bcm2835: Add Raspberry Pi Compute Module 4 Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-07 11:06 ` [PATCH V2 08/10] ARM: dts: " Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-07 11:06 ` [PATCH V2 09/10] ARM: dts: Add Raspberry Pi Compute Module 4 IO Board Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-09-04 14:52 ` nicolas saenz julienne 2021-09-04 14:52 ` nicolas saenz julienne 2021-09-05 10:33 ` Stefan Wahren 2021-09-05 10:33 ` Stefan Wahren 2021-08-07 11:06 ` [PATCH V2 10/10] arm64: dts: broadcom: Add reference to RPi CM4 " Stefan Wahren 2021-08-07 11:06 ` Stefan Wahren 2021-08-22 10:31 ` [PATCH V2 00/10] ARM: dts: Add Raspberry Pi CM4 & CM4 IO Board support Florian Fainelli 2021-08-22 10:31 ` Florian Fainelli 2021-08-30 8:46 ` nicolas saenz julienne 2021-08-30 8:46 ` nicolas saenz julienne 2021-09-04 14:45 ` nicolas saenz julienne 2021-09-04 14:45 ` nicolas saenz julienne
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