Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
Signed-off-by: Rob Clark robdclark@gmail.com --- drivers/gpu/drm/drm_dp_helper.c | 66 ++++++++++++++++++++++++++++++++--------- include/drm/drmP.h | 6 ++++ 2 files changed, 58 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 291734e..8e17f55 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -159,6 +159,46 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
+static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{ + size_t ret; + + mutex_lock(&aux->hw_mutex); + + DRM_DEBUG_DPCD("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name, + msg->request, msg->address, msg->size); + if (unlikely(drm_debug & DRM_UT_DPCD)) { + switch (msg->request & ~DP_AUX_I2C_MOT) { + case DP_AUX_NATIVE_WRITE: + case DP_AUX_I2C_WRITE: + print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET, + 16, 1, msg->buffer, msg->size, false); + break; + default: + break; + } + } + + ret = aux->transfer(aux, msg); + + DRM_DEBUG_DPCD("%s: reply=0x%02x, size=%zu\n", aux->name, msg->reply, ret); + if (unlikely(drm_debug & DRM_UT_DPCD)) { + switch (msg->request & ~DP_AUX_I2C_MOT) { + case DP_AUX_NATIVE_READ: + case DP_AUX_I2C_READ: + print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET, + 16, 1, msg->buffer, ret, false); + break; + default: + break; + } + } + + mutex_unlock(&aux->hw_mutex); + + return ret; +} + #define AUX_RETRY_INTERVAL 500 /* us */
/** @@ -194,9 +234,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
- mutex_lock(&aux->hw_mutex); - err = aux->transfer(aux, &msg); - mutex_unlock(&aux->hw_mutex); + err = aux_transfer(aux, &msg); if (err < 0) { if (err == -EBUSY) continue; @@ -212,15 +250,17 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, return err;
case DP_AUX_NATIVE_REPLY_NACK: + DRM_DEBUG_DPCD("native nack (result=%d, size=%zu)\n", err, msg.size); return -EIO;
case DP_AUX_NATIVE_REPLY_DEFER: + DRM_DEBUG_DPCD("native defer\n"); usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break; } }
- DRM_DEBUG_KMS("too many retries, giving up\n"); + DRM_DEBUG_DPCD("too many retries, giving up\n"); return -EIO; }
@@ -530,14 +570,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { - mutex_lock(&aux->hw_mutex); - ret = aux->transfer(aux, msg); - mutex_unlock(&aux->hw_mutex); + ret = aux_transfer(aux, msg); if (ret < 0) { if (ret == -EBUSY) continue;
- DRM_DEBUG_KMS("transaction failed: %d\n", ret); + DRM_DEBUG_DPCD("transaction failed: %d\n", ret); return ret; }
@@ -551,11 +589,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break;
case DP_AUX_NATIVE_REPLY_NACK: - DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size); + DRM_DEBUG_DPCD("native nack (result=%d, size=%zu)\n", ret, msg->size); return -EREMOTEIO;
case DP_AUX_NATIVE_REPLY_DEFER: - DRM_DEBUG_KMS("native defer\n"); + DRM_DEBUG_DPCD("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be @@ -582,12 +620,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret;
case DP_AUX_I2C_REPLY_NACK: - DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size); + DRM_DEBUG_DPCD("I2C nack (result=%d, size=%zu\n", ret, msg->size); aux->i2c_nack_count++; return -EREMOTEIO;
case DP_AUX_I2C_REPLY_DEFER: - DRM_DEBUG_KMS("I2C defer\n"); + DRM_DEBUG_DPCD("I2C defer\n"); /* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test @@ -604,7 +642,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
- DRM_DEBUG_KMS("too many retries, giving up\n"); + DRM_DEBUG_DPCD("too many retries, giving up\n"); return -EREMOTEIO; }
@@ -624,7 +662,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) { - DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n", + DRM_DEBUG_DPCD("Partial I2C reply: requested %zu bytes got %d bytes\n", msg.size, err); ret = err; } diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 8b5ce7c..f6c25cc 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -125,6 +125,7 @@ struct dma_buf_attachment; #define DRM_UT_KMS 0x04 #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 +#define DRM_UT_DPCD 0x20
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -217,6 +218,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_ATOMIC)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_DPCD(fmt, args...) \ + do { \ + if (unlikely(drm_debug & DRM_UT_DPCD)) \ + drm_ut_debug_printk(__func__, fmt, ##args); \ + } while (0)
/*@}*/