On 12/06/17 11:49, Ulf Hansson wrote:
> The MMC_CAP2_HC_ERASE_SZ is used only by a few mmc host drivers. Its intent
> is to enable eMMC's high-capacity erase size, as to improve the behaviour
> of the erase operations.
>
> However, for eMMCs supporting trim/discard, the MMC_CAP2_HC_ERASE_SZ
> becomes somewhat redundant. This because trim/discard operates on sectors
> and these commands takes precedence over erase commands, when supported.
>
> In addition, we should really avoid software configuration options that
> isn't necessary, but instead strive to deploy common behaviours. For these
> reasons, let's remove the capability bit for MMC_CAP2_HC_ERASE_SZ and the
> corresponding behaviour.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
> drivers/mmc/core/mmc.c | 3 +--
> drivers/mmc/host/sdhci-acpi.c | 1 -
> drivers/mmc/host/sdhci-brcmstb.c | 3 ---
> drivers/mmc/host/sdhci-pci-core.c | 4 +---
> include/linux/mmc/host.h | 1 -
> 5 files changed, 2 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index e504b66..d1a6d74 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1655,8 +1655,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
> * If enhanced_area_en is TRUE, host needs to enable ERASE_GRP_DEF
> * bit. This bit will be lost every time after a reset or power off.
> */
> - if (card->ext_csd.partition_setting_completed ||
> - (card->ext_csd.rev >= 3 && (host->caps2 & MMC_CAP2_HC_ERASE_SZ))) {
> + if (card->ext_csd.partition_setting_completed) {
PARTITION_SETTING_COMPLETED was added in eMMC v4.4 but ERASE_GROUP_DEF was
added in eMMC v4.3, so this doesn't work for v4.3 devices.
Why not enable it always? i.e.
if (card->ext_csd.rev >= 3) {
> err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> EXT_CSD_ERASE_GROUP_DEF, 1,
> card->ext_csd.generic_cmd6_time);
> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
> index 89d9a8c..cf66a3d 100644
> --- a/drivers/mmc/host/sdhci-acpi.c
> +++ b/drivers/mmc/host/sdhci-acpi.c
> @@ -274,7 +274,6 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_int_emmc = {
> .caps = MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
> MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR |
> MMC_CAP_CMD_DURING_TFR | MMC_CAP_WAIT_WHILE_BUSY,
> - .caps2 = MMC_CAP2_HC_ERASE_SZ,
> .flags = SDHCI_ACPI_RUNTIME_PM,
> .quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
> .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
> diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
> index 242c5dc..e2f6383 100644
> --- a/drivers/mmc/host/sdhci-brcmstb.c
> +++ b/drivers/mmc/host/sdhci-brcmstb.c
> @@ -89,9 +89,6 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
> goto err_clk;
> }
>
> - /* Enable MMC_CAP2_HC_ERASE_SZ for better max discard calculations */
> - host->mmc->caps2 |= MMC_CAP2_HC_ERASE_SZ;
> -
> sdhci_get_of_property(pdev);
> mmc_of_parse(host->mmc);
>
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index 8fa84a0..227a5cb 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -347,8 +347,7 @@ static inline void sdhci_pci_remove_own_cd(struct sdhci_pci_slot *slot)
> static int mfd_emmc_probe_slot(struct sdhci_pci_slot *slot)
> {
> slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE;
> - slot->host->mmc->caps2 |= MMC_CAP2_BOOTPART_NOACC |
> - MMC_CAP2_HC_ERASE_SZ;
> + slot->host->mmc->caps2 |= MMC_CAP2_BOOTPART_NOACC;
> return 0;
> }
>
> @@ -587,7 +586,6 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
> MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR |
> MMC_CAP_CMD_DURING_TFR |
> MMC_CAP_WAIT_WHILE_BUSY;
> - slot->host->mmc->caps2 |= MMC_CAP2_HC_ERASE_SZ;
> slot->hw_reset = sdhci_pci_int_hw_reset;
> if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BSW_EMMC)
> slot->host->timeout_clk = 1000; /* 1000 kHz i.e. 1 MHz */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 9209f95..c81380a 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -287,7 +287,6 @@ struct mmc_host {
> #define MMC_CAP2_HS200_1_2V_SDR (1 << 6) /* can support */
> #define MMC_CAP2_HS200 (MMC_CAP2_HS200_1_8V_SDR | \
> MMC_CAP2_HS200_1_2V_SDR)
> -#define MMC_CAP2_HC_ERASE_SZ (1 << 9) /* High-capacity erase size */
> #define MMC_CAP2_CD_ACTIVE_HIGH (1 << 10) /* Card-detect signal active high */
> #define MMC_CAP2_RO_ACTIVE_HIGH (1 << 11) /* Write-protect signal active high */
> #define MMC_CAP2_PACKED_RD (1 << 12) /* Allow packed read */
>
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