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SubjectRe: [PATCH v2 03/10] scsi: ufs: Add LCC quirk for host and device
On 2018-05-03 04:07, Asutosh Das wrote:
> LCC (Line Control Command) is being used for communication between
> UFS host and UFS device. But some hosts might have the issue with
> issuing the LCC commands to UFS device and in this case LCC could be
> explicitly disabled.
>
> But there could be a need where we don't want to disable the LCC
> on both host & device; hence this change splits the quirk in 2 parts
> one for host and one for device.
>
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
> ---
> drivers/scsi/ufs/ufshcd.c | 16 ++++++++++++++++
> drivers/scsi/ufs/ufshcd.h | 12 ++++++++++++
> 2 files changed, 28 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index f3083fe..6dabce8 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4116,6 +4116,11 @@ static int ufshcd_disable_tx_lcc(struct ufs_hba
> *hba, bool peer)
> return err;
> }
>
> +static inline int ufshcd_disable_host_tx_lcc(struct ufs_hba *hba)
> +{
> + return ufshcd_disable_tx_lcc(hba, false);
> +}
> +
> static inline int ufshcd_disable_device_tx_lcc(struct ufs_hba *hba)
> {
> return ufshcd_disable_tx_lcc(hba, true);
> @@ -4172,6 +4177,17 @@ static int ufshcd_link_startup(struct ufs_hba
> *hba)
> ufshcd_dme_set(hba, UIC_ARG_MIB(TX_LCC_ENABLE), 1);
> }
>
> + if (hba->quirks & UFSHCD_BROKEN_LCC_PROCESSING_ON_HOST) {
> + ret = ufshcd_disable_device_tx_lcc(hba);
> + if (ret)
> + goto out;
> + }
> +
> + if (hba->quirks & UFSHCD_BROKEN_LCC_PROCESSING_ON_DEVICE) {
> + ret = ufshcd_disable_host_tx_lcc(hba);
> + if (ret)
> + goto out;
> + }
> if (link_startup_again) {
> link_startup_again = false;
> retries = DME_LINKSTARTUP_RETRIES;
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index bb4ecfb..0417c42 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -598,6 +598,18 @@ struct ufs_hba {
> * TX_LCC.
> */
> #define UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE UFS_BIT(8)
> +
> + /*
> + * If UFS device is having issue in processing LCC (Line Control
> + * Command) coming from UFS host controller then enable this quirk.
> + * When this quirk is enabled, host controller driver should disable
> + * the LCC transmission on UFS host controller (by clearing
> + * TX_LCC_ENABLE attribute of host to 0).
> + */
> + #define UFSHCD_BROKEN_LCC_PROCESSING_ON_DEVICE 0x100
> +
> + #define UFSHCD_BROKEN_LCC_PROCESSING_ON_HOST 0x200
> +
> unsigned int quirks; /* Deviations from standard UFSHCI spec. */
>
> /* Device deviations from standard UFS device spec. */

Please check if these quirks are really needed for commercial version of
UFS host controllers.

--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

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