GMBUS HW supports 511Bytes as Max Bytes per single RD/WR op. Instead of enabling the 511Bytes per RD/WR cycle on legacy platforms for no absolute ROIs, this change allows the max bytes per op upto 511Bytes from Gen9 onwards.
v2: No Change. v3: Inline function for max_xfer_size and renaming of the macro.[Jani] v4: Extra brackets removed [ville] Commit msg is modified. v5: Adding the Reviewed-By received. v6: No Change.
Cc: Jani Nikula jani.nikula@intel.com Cc: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Ramalingam C ramalingam.c@intel.com Reviewed-by: Jani Nikula jani.nikula@intel.com --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_i2c.c | 11 +++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 822fee56931e..91d42b3e39ad 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3049,6 +3049,7 @@ enum i915_power_well_id { #define GMBUS_CYCLE_STOP (4 << 25) #define GMBUS_BYTE_COUNT_SHIFT 16 #define GMBUS_BYTE_COUNT_MAX 256U +#define GEN9_GMBUS_BYTE_COUNT_MAX 511U #define GMBUS_SLAVE_INDEX_SHIFT 8 #define GMBUS_SLAVE_ADDR_SHIFT 1 #define GMBUS_SLAVE_READ (1 << 0) diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 97606c1be70d..82bb9c33ab1c 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -361,6 +361,13 @@ gmbus_wait_idle(struct drm_i915_private *dev_priv) return ret; }
+static inline +unsigned int gmbus_max_xfer_size(struct drm_i915_private *dev_priv) +{ + return INTEL_GEN(dev_priv) >= 9 ? GEN9_GMBUS_BYTE_COUNT_MAX : + GMBUS_BYTE_COUNT_MAX; +} + static int gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv, unsigned short addr, u8 *buf, unsigned int len, @@ -400,7 +407,7 @@ gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg, int ret;
do { - len = min(rx_size, GMBUS_BYTE_COUNT_MAX); + len = min(rx_size, gmbus_max_xfer_size(dev_priv));
ret = gmbus_xfer_read_chunk(dev_priv, msg->addr, buf, len, gmbus1_index); @@ -462,7 +469,7 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg, int ret;
do { - len = min(tx_size, GMBUS_BYTE_COUNT_MAX); + len = min(tx_size, gmbus_max_xfer_size(dev_priv));
ret = gmbus_xfer_write_chunk(dev_priv, msg->addr, buf, len, gmbus1_index);