This is a note to let you know that I've just added the patch titled mmc: sdhci-acpi: Fix HS400 tuning for AMDI0040 to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-sdhci-acpi-fix-hs400-tuning-for-amdi0040.patch and it can be found in the queue-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 115177d5e1f2ed35fe3b97aadcf6e5ca2347322c Author: Raul E Rangel <rrangel@xxxxxxxxxxxx> Date: Wed Aug 19 13:00:19 2020 -0600 mmc: sdhci-acpi: Fix HS400 tuning for AMDI0040 [ Upstream commit 61d7437ed13906984c44697970ee792ac6271a31 ] The AMD eMMC Controller can only use the tuned clock while in HS200 and HS400 mode. If we switch to a different mode, we need to disable the tuned clock. If we have previously performed tuning and switch back to HS200 or HS400, we can re-enable the tuned clock. Previously the tuned clock was not getting disabled when switching to DDR52 which is part of the HS400 tuning sequence. Fixes: 34597a3f60b1 ("mmc: sdhci-acpi: Add support for ACPI HID of AMD Controller with HS400") Signed-off-by: Raul E Rangel <rrangel@xxxxxxxxxxxx> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Link: https://lore.kernel.org/r/20200819125832.v2.1.Ie8f0689ec9f449203328b37409d1cf06b565f331@changeid Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c index d8b76cb8698aa..2d9f79b50a7fa 100644 --- a/drivers/mmc/host/sdhci-acpi.c +++ b/drivers/mmc/host/sdhci-acpi.c @@ -535,6 +535,11 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_qcom_sd = { .caps = MMC_CAP_NONREMOVABLE, }; +struct amd_sdhci_host { + bool tuned_clock; + bool dll_enabled; +}; + /* AMD sdhci reset dll register. */ #define SDHCI_AMD_RESET_DLL_REGISTER 0x908 @@ -554,26 +559,66 @@ static void sdhci_acpi_amd_hs400_dll(struct sdhci_host *host) } /* - * For AMD Platform it is required to disable the tuning - * bit first controller to bring to HS Mode from HS200 - * mode, later enable to tune to HS400 mode. + * The initialization sequence for HS400 is: + * HS->HS200->Perform Tuning->HS->HS400 + * + * The re-tuning sequence is: + * HS400->DDR52->HS->HS200->Perform Tuning->HS->HS400 + * + * The AMD eMMC Controller can only use the tuned clock while in HS200 and HS400 + * mode. If we switch to a different mode, we need to disable the tuned clock. + * If we have previously performed tuning and switch back to HS200 or + * HS400, we can re-enable the tuned clock. + * */ static void amd_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { struct sdhci_host *host = mmc_priv(mmc); + struct sdhci_acpi_host *acpi_host = sdhci_priv(host); + struct amd_sdhci_host *amd_host = sdhci_acpi_priv(acpi_host); unsigned int old_timing = host->timing; + u16 val; sdhci_set_ios(mmc, ios); - if (old_timing == MMC_TIMING_MMC_HS200 && - ios->timing == MMC_TIMING_MMC_HS) - sdhci_writew(host, 0x9, SDHCI_HOST_CONTROL2); - if (old_timing != MMC_TIMING_MMC_HS400 && - ios->timing == MMC_TIMING_MMC_HS400) { - sdhci_writew(host, 0x80, SDHCI_HOST_CONTROL2); - sdhci_acpi_amd_hs400_dll(host); + + if (old_timing != host->timing && amd_host->tuned_clock) { + if (host->timing == MMC_TIMING_MMC_HS400 || + host->timing == MMC_TIMING_MMC_HS200) { + val = sdhci_readw(host, SDHCI_HOST_CONTROL2); + val |= SDHCI_CTRL_TUNED_CLK; + sdhci_writew(host, val, SDHCI_HOST_CONTROL2); + } else { + val = sdhci_readw(host, SDHCI_HOST_CONTROL2); + val &= ~SDHCI_CTRL_TUNED_CLK; + sdhci_writew(host, val, SDHCI_HOST_CONTROL2); + } + + /* DLL is only required for HS400 */ + if (host->timing == MMC_TIMING_MMC_HS400 && + !amd_host->dll_enabled) { + sdhci_acpi_amd_hs400_dll(host); + amd_host->dll_enabled = true; + } } } +static int amd_sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode) +{ + int err; + struct sdhci_host *host = mmc_priv(mmc); + struct sdhci_acpi_host *acpi_host = sdhci_priv(host); + struct amd_sdhci_host *amd_host = sdhci_acpi_priv(acpi_host); + + amd_host->tuned_clock = false; + + err = sdhci_execute_tuning(mmc, opcode); + + if (!err && !host->tuning_err) + amd_host->tuned_clock = true; + + return err; +} + static const struct sdhci_ops sdhci_acpi_ops_amd = { .set_clock = sdhci_set_clock, .set_bus_width = sdhci_set_bus_width, @@ -601,6 +646,7 @@ static int sdhci_acpi_emmc_amd_probe_slot(struct platform_device *pdev, host->mmc_host_ops.select_drive_strength = amd_select_drive_strength; host->mmc_host_ops.set_ios = amd_set_ios; + host->mmc_host_ops.execute_tuning = amd_sdhci_execute_tuning; return 0; } @@ -612,6 +658,7 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_amd_emmc = { SDHCI_QUIRK_32BIT_ADMA_SIZE, .quirks2 = SDHCI_QUIRK2_BROKEN_64_BIT_DMA, .probe_slot = sdhci_acpi_emmc_amd_probe_slot, + .priv_size = sizeof(struct amd_sdhci_host), }; struct sdhci_acpi_uid_slot {