From 4e6c2d58ba8649a6b505fc1461ccdedc583c3e36 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 19 Aug 2016 17:45:02 +0100 Subject: [PATCH] drm/i915: Take forcewake once for the entire GMBUS transaction As we do many register reads within a very short period of time, hold the GMBUS powerwell from start to finish. Signed-off-by: Chris Wilson Cc: David Weinehall Link: http://patchwork.freedesktop.org/patch/msgid/20160819164503.17845-1-chris@chris-wilson.co.uk Reviewed-by: David Weinehall --- drivers/gpu/drm/i915/intel_i2c.c | 131 +++++++++++++++++++-------------------- 1 file changed, 63 insertions(+), 68 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index a4ca205..79aab9a 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -255,67 +255,59 @@ intel_gpio_setup(struct intel_gmbus *bus, unsigned int pin) algo->data = bus; } -static int -gmbus_wait_hw_status(struct drm_i915_private *dev_priv, - u32 gmbus2_status, - u32 gmbus4_irq_en) +static int gmbus_wait(struct drm_i915_private *dev_priv, u32 status, u32 irq_en) { - int i; - u32 gmbus2 = 0; DEFINE_WAIT(wait); - - if (!HAS_GMBUS_IRQ(dev_priv)) - gmbus4_irq_en = 0; + u32 gmbus2; + int ret; /* Important: The hw handles only the first bit, so set only one! Since * we also need to check for NAKs besides the hw ready/idle signal, we - * need to wake up periodically and check that ourselves. */ - I915_WRITE(GMBUS4, gmbus4_irq_en); - - for (i = 0; i < msecs_to_jiffies_timeout(50); i++) { - prepare_to_wait(&dev_priv->gmbus_wait_queue, &wait, - TASK_UNINTERRUPTIBLE); + * need to wake up periodically and check that ourselves. + */ + if (!HAS_GMBUS_IRQ(dev_priv)) + irq_en = 0; - gmbus2 = I915_READ_NOTRACE(GMBUS2); - if (gmbus2 & (GMBUS_SATOER | gmbus2_status)) - break; + add_wait_queue(&dev_priv->gmbus_wait_queue, &wait); + I915_WRITE_FW(GMBUS4, irq_en); - schedule_timeout(1); - } - finish_wait(&dev_priv->gmbus_wait_queue, &wait); + status |= GMBUS_SATOER; + ret = wait_for_us((gmbus2 = I915_READ_FW(GMBUS2)) & status, 2); + if (ret) + ret = wait_for((gmbus2 = I915_READ_FW(GMBUS2)) & status, 50); - I915_WRITE(GMBUS4, 0); + I915_WRITE_FW(GMBUS4, 0); + remove_wait_queue(&dev_priv->gmbus_wait_queue, &wait); if (gmbus2 & GMBUS_SATOER) return -ENXIO; - if (gmbus2 & gmbus2_status) - return 0; - return -ETIMEDOUT; + + return ret; } static int gmbus_wait_idle(struct drm_i915_private *dev_priv) { + DEFINE_WAIT(wait); + u32 irq_enable; int ret; - if (!HAS_GMBUS_IRQ(dev_priv)) - return intel_wait_for_register(dev_priv, - GMBUS2, GMBUS_ACTIVE, 0, - 10); - /* Important: The hw handles only the first bit, so set only one! */ - I915_WRITE(GMBUS4, GMBUS_IDLE_EN); + irq_enable = 0; + if (HAS_GMBUS_IRQ(dev_priv)) + irq_enable = GMBUS_IDLE_EN; - ret = wait_event_timeout(dev_priv->gmbus_wait_queue, - (I915_READ_NOTRACE(GMBUS2) & GMBUS_ACTIVE) == 0, - msecs_to_jiffies_timeout(10)); + add_wait_queue(&dev_priv->gmbus_wait_queue, &wait); + I915_WRITE_FW(GMBUS4, irq_enable); - I915_WRITE(GMBUS4, 0); + ret = intel_wait_for_register_fw(dev_priv, + GMBUS2, GMBUS_ACTIVE, 0, + 10); - if (ret) - return 0; - else - return -ETIMEDOUT; + I915_WRITE_FW(GMBUS4, 0); + remove_wait_queue(&dev_priv->gmbus_wait_queue, &wait); + + return ret; } static int @@ -323,22 +315,21 @@ gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv, unsigned short addr, u8 *buf, unsigned int len, u32 gmbus1_index) { - I915_WRITE(GMBUS1, - gmbus1_index | - GMBUS_CYCLE_WAIT | - (len << GMBUS_BYTE_COUNT_SHIFT) | - (addr << GMBUS_SLAVE_ADDR_SHIFT) | - GMBUS_SLAVE_READ | GMBUS_SW_RDY); + I915_WRITE_FW(GMBUS1, + gmbus1_index | + GMBUS_CYCLE_WAIT | + (len << GMBUS_BYTE_COUNT_SHIFT) | + (addr << GMBUS_SLAVE_ADDR_SHIFT) | + GMBUS_SLAVE_READ | GMBUS_SW_RDY); while (len) { int ret; u32 val, loop = 0; - ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY, - GMBUS_HW_RDY_EN); + ret = gmbus_wait(dev_priv, GMBUS_HW_RDY, GMBUS_HW_RDY_EN); if (ret) return ret; - val = I915_READ(GMBUS3); + val = I915_READ_FW(GMBUS3); do { *buf++ = val & 0xff; val >>= 8; @@ -385,12 +376,12 @@ gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv, len -= 1; } - I915_WRITE(GMBUS3, val); - I915_WRITE(GMBUS1, - GMBUS_CYCLE_WAIT | - (chunk_size << GMBUS_BYTE_COUNT_SHIFT) | - (addr << GMBUS_SLAVE_ADDR_SHIFT) | - GMBUS_SLAVE_WRITE | GMBUS_SW_RDY); + I915_WRITE_FW(GMBUS3, val); + I915_WRITE_FW(GMBUS1, + GMBUS_CYCLE_WAIT | + (chunk_size << GMBUS_BYTE_COUNT_SHIFT) | + (addr << GMBUS_SLAVE_ADDR_SHIFT) | + GMBUS_SLAVE_WRITE | GMBUS_SW_RDY); while (len) { int ret; @@ -399,10 +390,9 @@ gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv, val |= *buf++ << (8 * loop); } while (--len && ++loop < 4); - I915_WRITE(GMBUS3, val); + I915_WRITE_FW(GMBUS3, val); - ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY, - GMBUS_HW_RDY_EN); + ret = gmbus_wait(dev_priv, GMBUS_HW_RDY, GMBUS_HW_RDY_EN); if (ret) return ret; } @@ -460,13 +450,13 @@ gmbus_xfer_index_read(struct drm_i915_private *dev_priv, struct i2c_msg *msgs) /* GMBUS5 holds 16-bit index */ if (gmbus5) - I915_WRITE(GMBUS5, gmbus5); + I915_WRITE_FW(GMBUS5, gmbus5); ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus1_index); /* Clear GMBUS5 after each index transfer */ if (gmbus5) - I915_WRITE(GMBUS5, 0); + I915_WRITE_FW(GMBUS5, 0); return ret; } @@ -478,11 +468,15 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) struct intel_gmbus, adapter); struct drm_i915_private *dev_priv = bus->dev_priv; + const unsigned int fw = + intel_uncore_forcewake_for_reg(dev_priv, GMBUS0, + FW_REG_READ | FW_REG_WRITE); int i = 0, inc, try = 0; int ret = 0; + intel_uncore_forcewake_get(dev_priv, fw); retry: - I915_WRITE(GMBUS0, bus->reg0); + I915_WRITE_FW(GMBUS0, bus->reg0); for (; i < num; i += inc) { inc = 1; @@ -496,8 +490,8 @@ retry: } if (!ret) - ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_WAIT_PHASE, - GMBUS_HW_WAIT_EN); + ret = gmbus_wait(dev_priv, + GMBUS_HW_WAIT_PHASE, GMBUS_HW_WAIT_EN); if (ret == -ETIMEDOUT) goto timeout; else if (ret) @@ -508,7 +502,7 @@ retry: * a STOP on the very first cycle. To simplify the code we * unconditionally generate the STOP condition with an additional gmbus * cycle. */ - I915_WRITE(GMBUS1, GMBUS_CYCLE_STOP | GMBUS_SW_RDY); + I915_WRITE_FW(GMBUS1, GMBUS_CYCLE_STOP | GMBUS_SW_RDY); /* Mark the GMBUS interface as disabled after waiting for idle. * We will re-enable it at the start of the next xfer, @@ -519,7 +513,7 @@ retry: adapter->name); ret = -ETIMEDOUT; } - I915_WRITE(GMBUS0, 0); + I915_WRITE_FW(GMBUS0, 0); ret = ret ?: i; goto out; @@ -548,9 +542,9 @@ clear_err: * of resetting the GMBUS controller and so clearing the * BUS_ERROR raised by the slave's NAK. */ - I915_WRITE(GMBUS1, GMBUS_SW_CLR_INT); - I915_WRITE(GMBUS1, 0); - I915_WRITE(GMBUS0, 0); + I915_WRITE_FW(GMBUS1, GMBUS_SW_CLR_INT); + I915_WRITE_FW(GMBUS1, 0); + I915_WRITE_FW(GMBUS0, 0); DRM_DEBUG_KMS("GMBUS [%s] NAK for addr: %04x %c(%d)\n", adapter->name, msgs[i].addr, @@ -573,7 +567,7 @@ clear_err: timeout: DRM_DEBUG_KMS("GMBUS [%s] timed out, falling back to bit banging on pin %d\n", bus->adapter.name, bus->reg0 & 0xff); - I915_WRITE(GMBUS0, 0); + I915_WRITE_FW(GMBUS0, 0); /* * Hardware may not support GMBUS over these pins? Try GPIO bitbanging @@ -582,6 +576,7 @@ timeout: ret = -EAGAIN; out: + intel_uncore_forcewake_put(dev_priv, fw); return ret; } -- 2.7.4