[PATCH v3 0/3] ufs: Add callback for vendor-specific RTT capability

[PATCH v3 0/3] ufs: Add callback for vendor-specific RTT capability

[ed.tsai]

From: Ed Tsai <ed.tsai@mediatek.com>

The first patch adds the get_hba_nortt() callback to the UFS core layer,
allowing vendor drivers to provide dynamic, platform-specific RTT
capability handling.

The second patch implements this callback in the MediaTek UFS driver,
distinguishing between legacy platforms (which require the RTT to be
limited to 2) and newer MT6995 B0+ platforms (which can use the value
from the capability register directly).

The third patch removes the max_num_rtt field from ufs_hba_variant_ops
as it is now replaced by the get_hba_nortt() callback.

Changes in v3:
- Fix incomplete v2 that was sent prematurely - now properly removes
  max_num_rtt field in patch 3

Changes in v2:
- Keep max_num_rtt field in patch 1 to maintain bisectability
- Split removal of max_num_rtt into a separate patch (patch 3)

Ed Tsai (3):
  ufs: core: Add get_hba_nortt callback for vendor-specific RTT
    capability
  ufs: mediatek: Implement get_hba_nortt callback for RTT capability
  ufs: core: Remove max_num_rtt field from ufs_hba_variant_ops

 drivers/ufs/core/ufshcd.c       |  9 +++++----
 drivers/ufs/host/ufs-mediatek.c | 12 +++++++++++-
 drivers/ufs/host/ufs-mediatek.h |  4 ++--
 include/ufs/ufshcd.h            |  5 +++--
 4 files changed, 21 insertions(+), 9 deletions(-)

-- 
2.45.2

[PATCH v3 1/3] ufs: core: Add get_hba_nortt callback for vendor-specific RTT capability

[ed.tsai]

From: Ed Tsai <ed.tsai@mediatek.com>

The number of outstanding RTTs read from host controller capability
register is problematic on some platforms. Add a new vendor callback
get_hba_nortt() to allow platform vendors to override the default RTT
capability value with platform-specific handling.

This patch keeps max_num_rtt field for bisectability and will be removed
in a later patch once all platforms are migrated.

Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
---
 drivers/ufs/core/ufshcd.c | 5 ++++-
 include/ufs/ufshcd.h      | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index c3f08957d179..382b6041c716 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2529,7 +2529,10 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba)
 	hba->nutmrs =
 	((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1;
 
-	hba->nortt = FIELD_GET(MASK_NUMBER_OUTSTANDING_RTT, hba->capabilities) + 1;
+	if (hba->vops && hba->vops->get_hba_nortt)
+		hba->nortt = hba->vops->get_hba_nortt(hba);
+	else
+		hba->nortt = FIELD_GET(MASK_NUMBER_OUTSTANDING_RTT, hba->capabilities) + 1;
 
 	/* Read crypto capabilities */
 	err = ufshcd_hba_init_crypto_capabilities(hba);
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index cfbc75d8df83..421c286481e8 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -415,6 +415,8 @@ struct ufshcd_tx_eq_params {
  * @get_rx_fom: called to get Figure of Merit (FOM) value.
  * @tx_eqtr_notify: called before and after TX Equalization Training procedure
  *	to allow platform vendor specific configs to take place.
+ * @get_hba_nortt: called to get maximum number of outstanding RTTs supported by
+ *	the controller.
  */
 struct ufs_hba_variant_ops {
 	const char *name;
@@ -477,6 +479,7 @@ struct ufs_hba_variant_ops {
 	int	(*tx_eqtr_notify)(struct ufs_hba *hba,
 				  enum ufs_notify_change_status status,
 				  struct ufs_pa_layer_attr *pwr_mode);
+	int	(*get_hba_nortt)(struct ufs_hba *hba);
 };
 
 /* clock gating state  */
-- 
2.45.2

Re: [PATCH v3 1/3] ufs: core: Add get_hba_nortt callback for vendor-specific RTT capability

[Peter Wang (王信友)]

On Mon, 2026-06-15 at 13:57 +0800, ed.tsai@mediatek.com wrote:
> From: Ed Tsai <ed.tsai@mediatek.com>
> 
> The number of outstanding RTTs read from host controller capability
> register is problematic on some platforms. Add a new vendor callback
> get_hba_nortt() to allow platform vendors to override the default RTT
> capability value with platform-specific handling.
> 
> This patch keeps max_num_rtt field for bisectability and will be
> removed
> in a later patch once all platforms are migrated.
> 
> Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
> ---

Reviewed-by: Peter Wang <peter.wang@mediatek.com>

Re: [PATCH v3 1/3] ufs: core: Add get_hba_nortt callback for vendor-specific RTT capability

[Bart Van Assche]

On 6/14/26 10:57 PM, ed.tsai@mediatek.com wrote:
> The number of outstanding RTTs read from host controller capability
> register is problematic on some platforms. Add a new vendor callback
> get_hba_nortt() to allow platform vendors to override the default RTT
> capability value with platform-specific handling.
> 
> This patch keeps max_num_rtt field for bisectability and will be removed
> in a later patch once all platforms are migrated.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

[PATCH v3 2/3] ufs: mediatek: Implement get_hba_nortt callback for RTT capability

[ed.tsai]

From: Ed Tsai <ed.tsai@mediatek.com>

Implement the get_hba_nortt callback to handle platform-specific RTT
capability differences:

- For legacy platforms and IP versions before MT6995 B0, the RTT
  capability from host controller register is problematic, so limit
  it to 2 (MTK_MAX_NUM_RTT_LEGACY).

- For MT6995 B0 and later platforms, the issue is fixed and the
  value from host controller capability register can be used directly.

This replaces the previous max_num_rtt field in ufs_hba_variant_ops
with dynamic platform-specific logic.

Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/ufs/host/ufs-mediatek.c | 12 +++++++++++-
 drivers/ufs/host/ufs-mediatek.h |  4 ++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-mediatek.c
index 3991a51263a6..58701ca95edd 100644
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -2183,6 +2183,16 @@ static int ufs_mtk_clk_scale_notify(struct ufs_hba *hba, bool scale_up,
 	return 0;
 }
 
+static int ufs_mtk_get_hba_nortt(struct ufs_hba *hba)
+{
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+	if (host->legacy_ip_ver || host->ip_ver < IP_VER_MT6995_B0)
+		return MTK_MAX_NUM_RTT_LEGACY;
+
+	return FIELD_GET(MASK_NUMBER_OUTSTANDING_RTT, hba->capabilities) + 1;
+}
+
 static int ufs_mtk_get_hba_mac(struct ufs_hba *hba)
 {
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
@@ -2322,7 +2332,6 @@ static void ufs_mtk_config_scsi_dev(struct scsi_device *sdev)
  */
 static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 	.name                = "mediatek.ufshci",
-	.max_num_rtt         = MTK_MAX_NUM_RTT,
 	.init                = ufs_mtk_init,
 	.get_ufs_hci_version = ufs_mtk_get_ufs_hci_version,
 	.setup_clocks        = ufs_mtk_setup_clocks,
@@ -2339,6 +2348,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 	.event_notify        = ufs_mtk_event_notify,
 	.config_scaling_param = ufs_mtk_config_scaling_param,
 	.clk_scale_notify    = ufs_mtk_clk_scale_notify,
+	.get_hba_nortt       = ufs_mtk_get_hba_nortt,
 	/* mcq vops */
 	.get_hba_mac         = ufs_mtk_get_hba_mac,
 	.op_runtime_config   = ufs_mtk_op_runtime_config,
diff --git a/drivers/ufs/host/ufs-mediatek.h b/drivers/ufs/host/ufs-mediatek.h
index 8547a6f04990..73cdc726f290 100644
--- a/drivers/ufs/host/ufs-mediatek.h
+++ b/drivers/ufs/host/ufs-mediatek.h
@@ -203,8 +203,8 @@ struct ufs_mtk_host {
 /* MTK delay of autosuspend: 500 ms */
 #define MTK_RPM_AUTOSUSPEND_DELAY_MS 500
 
-/* MTK RTT support number */
-#define MTK_MAX_NUM_RTT 2
+/* MTK RTT support number for platforms before MT6995 B0 */
+#define MTK_MAX_NUM_RTT_LEGACY 2
 
 /* UFSHCI MTK ip version value */
 enum {
-- 
2.45.2

[PATCH v3 3/3] ufs: core: Remove max_num_rtt field from ufs_hba_variant_ops

[ed.tsai]

From: Ed Tsai <ed.tsai@mediatek.com>

Remove the max_num_rtt field from ufs_hba_variant_ops as it has been
replaced by the get_hba_nortt() callback which provides more flexible
platform-specific RTT capability handling.

Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
---
 drivers/ufs/core/ufshcd.c | 4 +---
 include/ufs/ufshcd.h      | 2 --
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 382b6041c716..00072bff9dcd 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -8557,8 +8557,6 @@ static void ufshcd_set_rtt(struct ufs_hba *hba)
 	struct ufs_dev_info *dev_info = &hba->dev_info;
 	u32 rtt = 0;
 	u32 dev_rtt = 0;
-	int host_rtt_cap = hba->vops && hba->vops->max_num_rtt ?
-			   hba->vops->max_num_rtt : hba->nortt;
 
 	/* RTT override makes sense only for UFS-4.0 and above */
 	if (dev_info->wspecversion < 0x400)
@@ -8574,7 +8572,7 @@ static void ufshcd_set_rtt(struct ufs_hba *hba)
 	if (dev_rtt != DEFAULT_MAX_NUM_RTT)
 		return;
 
-	rtt = min_t(int, dev_info->rtt_cap, host_rtt_cap);
+	rtt = min_t(int, dev_info->rtt_cap, hba->nortt);
 
 	if (rtt == dev_rtt)
 		return;
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 421c286481e8..13d0d7798294 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -370,7 +370,6 @@ struct ufshcd_tx_eq_params {
 /**
  * struct ufs_hba_variant_ops - variant specific callbacks
  * @name: variant name
- * @max_num_rtt: maximum RTT supported by the host
  * @init: called when the driver is initialized
  * @exit: called to cleanup everything done in init
  * @set_dma_mask: For setting another DMA mask than indicated by the 64AS
@@ -420,7 +419,6 @@ struct ufshcd_tx_eq_params {
  */
 struct ufs_hba_variant_ops {
 	const char *name;
-	int	max_num_rtt;
 	int	(*init)(struct ufs_hba *);
 	void    (*exit)(struct ufs_hba *);
 	u32	(*get_ufs_hci_version)(struct ufs_hba *);
-- 
2.45.2

Re: [PATCH v3 3/3] ufs: core: Remove max_num_rtt field from ufs_hba_variant_ops

[Peter Wang (王信友)]

On Mon, 2026-06-15 at 13:57 +0800, ed.tsai@mediatek.com wrote:
> From: Ed Tsai <ed.tsai@mediatek.com>
> 
> Remove the max_num_rtt field from ufs_hba_variant_ops as it has been
> replaced by the get_hba_nortt() callback which provides more flexible
> platform-specific RTT capability handling.
> 
> Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
> ---

Reviewed-by: Peter Wang <peter.wang@mediatek.com>

Re: [PATCH v3 3/3] ufs: core: Remove max_num_rtt field from ufs_hba_variant_ops

[Bart Van Assche]

On 6/14/26 10:57 PM, ed.tsai@mediatek.com wrote:
> Remove the max_num_rtt field from ufs_hba_variant_ops as it has been
> replaced by the get_hba_nortt() callback which provides more flexible
> platform-specific RTT capability handling.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>