| Message ID | 20210507212505.1224111-4-swboyd@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | drm/msm/dp: Simplify aux code | expand |
On 2021-05-07 14:25, Stephen Boyd wrote: > Let's look at the irq status bits after a transfer and see if we got a > nack or a defer or a timeout, instead of telling drm layers that > everything was fine, while still printing an error message. I wasn't > sure about NACK+DEFER so I lumped all those various errors along with a > nack so that the drm core can figure out that things are just not going > well. The important thing is that we're now returning -ETIMEDOUT when > the message times out and nacks for bad addresses. > > Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Cc: Abhinav Kumar <abhinavk@codeaurora.org> > Cc: Kuogee Hsieh <khsieh@codeaurora.org> > Cc: aravindh@codeaurora.org > Cc: Sean Paul <sean@poorly.run> > Signed-off-by: Stephen Boyd <swboyd@chromium.org> > --- > drivers/gpu/drm/msm/dp/dp_aux.c | 140 ++++++++++++++------------------ > drivers/gpu/drm/msm/dp/dp_aux.h | 8 -- > 2 files changed, 61 insertions(+), 87 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c > b/drivers/gpu/drm/msm/dp/dp_aux.c > index b49810396513..4a3293b590b0 100644 > --- a/drivers/gpu/drm/msm/dp/dp_aux.c > +++ b/drivers/gpu/drm/msm/dp/dp_aux.c > @@ -9,7 +9,15 @@ > #include "dp_reg.h" > #include "dp_aux.h" > > -#define DP_AUX_ENUM_STR(x) #x > +enum msm_dp_aux_err { > + DP_AUX_ERR_NONE, > + DP_AUX_ERR_ADDR, > + DP_AUX_ERR_TOUT, > + DP_AUX_ERR_NACK, > + DP_AUX_ERR_DEFER, > + DP_AUX_ERR_NACK_DEFER, > + DP_AUX_ERR_PHY, > +}; > > struct dp_aux_private { > struct device *dev; > @@ -18,7 +26,7 @@ struct dp_aux_private { > struct mutex mutex; > struct completion comp; > > - u32 aux_error_num; > + enum msm_dp_aux_err aux_error_num; > u32 retry_cnt; > bool cmd_busy; > bool native; > @@ -33,62 +41,45 @@ struct dp_aux_private { > > #define MAX_AUX_RETRIES 5 > > -static const char *dp_aux_get_error(u32 aux_error) > -{ > - switch (aux_error) { > - case DP_AUX_ERR_NONE: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_NONE); > - case DP_AUX_ERR_ADDR: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_ADDR); > - case DP_AUX_ERR_TOUT: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_TOUT); > - case DP_AUX_ERR_NACK: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_NACK); > - case DP_AUX_ERR_DEFER: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_DEFER); > - case DP_AUX_ERR_NACK_DEFER: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_NACK_DEFER); > - default: > - return "unknown"; > - } > -} > - > -static u32 dp_aux_write(struct dp_aux_private *aux, > +static ssize_t dp_aux_write(struct dp_aux_private *aux, > struct drm_dp_aux_msg *msg) > { > - u32 data[4], reg, len; > + u8 data[4]; > + u32 reg; > + ssize_t len; > u8 *msgdata = msg->buffer; > int const AUX_CMD_FIFO_LEN = 128; > int i = 0; > > if (aux->read) > - len = 4; > + len = 0; > else > - len = msg->size + 4; > + len = msg->size; > > /* > * cmd fifo only has depth of 144 bytes > * limit buf length to 128 bytes here > */ > - if (len > AUX_CMD_FIFO_LEN) { > + if (len > AUX_CMD_FIFO_LEN - 4) { > DRM_ERROR("buf size greater than allowed size of 128 bytes\n"); > - return 0; > + return -EINVAL; > } > > /* Pack cmd and write to HW */ > - data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */ > + data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */ > if (aux->read) > - data[0] |= BIT(4); /* R/W */ > + data[0] |= BIT(4); /* R/W */ > > - data[1] = (msg->address >> 8) & 0xff; /* addr[15:8] */ > - data[2] = msg->address & 0xff; /* addr[7:0] */ > - data[3] = (msg->size - 1) & 0xff; /* len[7:0] */ > + data[1] = msg->address >> 8; /* addr[15:8] */ > + data[2] = msg->address; /* addr[7:0] */ > + data[3] = msg->size - 1; /* len[7:0] */ > > - for (i = 0; i < len; i++) { > + for (i = 0; i < len + 4; i++) { > reg = (i < 4) ? data[i] : msgdata[i - 4]; > + reg <<= DP_AUX_DATA_OFFSET; > + reg &= DP_AUX_DATA_MASK; > + reg |= DP_AUX_DATA_WRITE; > /* index = 0, write */ > - reg = (((reg) << DP_AUX_DATA_OFFSET) > - & DP_AUX_DATA_MASK) | DP_AUX_DATA_WRITE; > if (i == 0) > reg |= DP_AUX_DATA_INDEX_WRITE; > aux->catalog->aux_data = reg; > @@ -116,39 +107,27 @@ static u32 dp_aux_write(struct dp_aux_private > *aux, > return len; > } > > -static int dp_aux_cmd_fifo_tx(struct dp_aux_private *aux, > +static ssize_t dp_aux_cmd_fifo_tx(struct dp_aux_private *aux, > struct drm_dp_aux_msg *msg) > { > - u32 ret, len, timeout; > - int aux_timeout_ms = HZ/4; > + ssize_t ret; > + unsigned long time_left; > > reinit_completion(&aux->comp); > > - len = dp_aux_write(aux, msg); > - if (len == 0) { > - DRM_ERROR("DP AUX write failed\n"); > - return -EINVAL; > - } > + ret = dp_aux_write(aux, msg); > + if (ret < 0) > + return ret; > > - timeout = wait_for_completion_timeout(&aux->comp, aux_timeout_ms); > - if (!timeout) { > - DRM_ERROR("aux %s timeout\n", (aux->read ? "read" : "write")); > + time_left = wait_for_completion_timeout(&aux->comp, > + msecs_to_jiffies(250)); > + if (!time_left) > return -ETIMEDOUT; > - } > - > - if (aux->aux_error_num == DP_AUX_ERR_NONE) { > - ret = len; > - } else { > - DRM_ERROR_RATELIMITED("aux err: %s\n", > - dp_aux_get_error(aux->aux_error_num)); > - > - ret = -EINVAL; > - } > > return ret; > } > > -static void dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, > +static ssize_t dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, > struct drm_dp_aux_msg *msg) > { > u32 data; > @@ -175,9 +154,10 @@ static void dp_aux_cmd_fifo_rx(struct > dp_aux_private *aux, > > actual_i = (data >> DP_AUX_DATA_INDEX_OFFSET) & 0xFF; > if (i != actual_i) > - DRM_ERROR("Index mismatch: expected %d, found %d\n", > - i, actual_i); > + break; > } > + > + return i; > } > > static void dp_aux_native_handler(struct dp_aux_private *aux, u32 isr) > @@ -367,36 +347,38 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux > *dp_aux, > } > > ret = dp_aux_cmd_fifo_tx(aux, msg); > - > if (ret < 0) { > if (aux->native) { > aux->retry_cnt++; > if (!(aux->retry_cnt % MAX_AUX_RETRIES)) > dp_catalog_aux_update_cfg(aux->catalog); > } > - usleep_range(400, 500); /* at least 400us to next try */ > - goto unlock_exit; > - } 1) dp_catalog_aux_update_cfg(aux->catalog) will not work without dp_catalog_aux_reset(aux->catalog); dp_catalog_aux_reset(aux->catalog) will reset hpd control block and potentially cause pending hpd interrupts got lost. Therefore I think we should not do dp_catalog_aux_update_cfg(aux->catalog) for now. reset aux controller will reset hpd control block probolem will be fixed at next chipset. after that we can add dp_catalog_aux_update_cfg(aux->catalog) followed by dp_catalog_aux_reset(aux->catalog) back at next chipset. 2) according to DP specification, aux read/write failed have to wait at least 400us before next try can start. Otherwise, DP compliant test will failed > - > - if (aux->aux_error_num == DP_AUX_ERR_NONE) { > - if (aux->read) > - dp_aux_cmd_fifo_rx(aux, msg); > - > - msg->reply = aux->native ? > - DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK; > } else { > - /* Reply defer to retry */ > - msg->reply = aux->native ? > - DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER; > + aux->retry_cnt = 0; > + switch (aux->aux_error_num) { > + case DP_AUX_ERR_NONE: > + if (aux->read) > + ret = dp_aux_cmd_fifo_rx(aux, msg); > + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_ACK : > DP_AUX_I2C_REPLY_ACK; > + break; > + case DP_AUX_ERR_DEFER: > + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_DEFER : > DP_AUX_I2C_REPLY_DEFER; > + break; > + case DP_AUX_ERR_PHY: > + case DP_AUX_ERR_ADDR: > + case DP_AUX_ERR_NACK: > + case DP_AUX_ERR_NACK_DEFER: > + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_NACK : > DP_AUX_I2C_REPLY_NACK; > + break; > + case DP_AUX_ERR_TOUT: > + ret = -ETIMEDOUT; > + break; > + } > } > > - /* Return requested size for success or retry */ > - ret = msg->size; > - aux->retry_cnt = 0; > - > -unlock_exit: > aux->cmd_busy = false; > mutex_unlock(&aux->mutex); > + > return ret; > } > > diff --git a/drivers/gpu/drm/msm/dp/dp_aux.h > b/drivers/gpu/drm/msm/dp/dp_aux.h > index f8b8ba919465..0728cc09c9ec 100644 > --- a/drivers/gpu/drm/msm/dp/dp_aux.h > +++ b/drivers/gpu/drm/msm/dp/dp_aux.h > @@ -9,14 +9,6 @@ > #include "dp_catalog.h" > #include <drm/drm_dp_helper.h> > > -#define DP_AUX_ERR_NONE 0 > -#define DP_AUX_ERR_ADDR -1 > -#define DP_AUX_ERR_TOUT -2 > -#define DP_AUX_ERR_NACK -3 > -#define DP_AUX_ERR_DEFER -4 > -#define DP_AUX_ERR_NACK_DEFER -5 > -#define DP_AUX_ERR_PHY -6 > - > int dp_aux_register(struct drm_dp_aux *dp_aux); > void dp_aux_unregister(struct drm_dp_aux *dp_aux); > void dp_aux_isr(struct drm_dp_aux *dp_aux);
Quoting khsieh@codeaurora.org (2021-05-24 09:33:49) > On 2021-05-07 14:25, Stephen Boyd wrote: > > @@ -367,36 +347,38 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux > > *dp_aux, > > } > > > > ret = dp_aux_cmd_fifo_tx(aux, msg); > > - > > if (ret < 0) { > > if (aux->native) { > > aux->retry_cnt++; > > if (!(aux->retry_cnt % MAX_AUX_RETRIES)) > > dp_catalog_aux_update_cfg(aux->catalog); > > } > > - usleep_range(400, 500); /* at least 400us to next try */ > > - goto unlock_exit; > > - } > > 1) dp_catalog_aux_update_cfg(aux->catalog) will not work without > dp_catalog_aux_reset(aux->catalog); > dp_catalog_aux_reset(aux->catalog) will reset hpd control block and > potentially cause pending hpd interrupts got lost. > Therefore I think we should not do > dp_catalog_aux_update_cfg(aux->catalog) for now. > reset aux controller will reset hpd control block probolem will be fixed > at next chipset. > after that we can add dp_catalog_aux_update_cfg(aux->catalog) followed > by dp_catalog_aux_reset(aux->catalog) back at next chipset. Hmm ok. So the phy calibration logic that tweaks the tuning values is never used? Why can't the phy be tuned while it is active? I don't understand why we would ever want to reset the aux phy when changing the settings for a retry. Either way, this is not actually changing in this patch so it would be another patch to remove this code. > > 2) according to DP specification, aux read/write failed have to wait at > least 400us before next try can start. > Otherwise, DP compliant test will failed Yes. The caller of this function, drm_dp_dpcd_access(), has the delay already if (ret != 0 && ret != -ETIMEDOUT) { usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); } so this delay here is redundant.
On 2021-05-24 12:19, Stephen Boyd wrote: > Quoting khsieh@codeaurora.org (2021-05-24 09:33:49) >> On 2021-05-07 14:25, Stephen Boyd wrote: >> > @@ -367,36 +347,38 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux >> > *dp_aux, >> > } >> > >> > ret = dp_aux_cmd_fifo_tx(aux, msg); >> > - >> > if (ret < 0) { >> > if (aux->native) { >> > aux->retry_cnt++; >> > if (!(aux->retry_cnt % MAX_AUX_RETRIES)) >> > dp_catalog_aux_update_cfg(aux->catalog); >> > } >> > - usleep_range(400, 500); /* at least 400us to next try */ >> > - goto unlock_exit; >> > - } >> >> 1) dp_catalog_aux_update_cfg(aux->catalog) will not work without >> dp_catalog_aux_reset(aux->catalog); >> dp_catalog_aux_reset(aux->catalog) will reset hpd control block and >> potentially cause pending hpd interrupts got lost. >> Therefore I think we should not do >> dp_catalog_aux_update_cfg(aux->catalog) for now. >> reset aux controller will reset hpd control block probolem will be >> fixed >> at next chipset. >> after that we can add dp_catalog_aux_update_cfg(aux->catalog) followed >> by dp_catalog_aux_reset(aux->catalog) back at next chipset. > > Hmm ok. So the phy calibration logic that tweaks the tuning values is > never used? Why can't the phy be tuned while it is active? I don't > understand why we would ever want to reset the aux phy when changing > the > settings for a retry. Either way, this is not actually changing in this > patch so it would be another patch to remove this code. ok, > >> >> 2) according to DP specification, aux read/write failed have to wait >> at >> least 400us before next try can start. >> Otherwise, DP compliant test will failed > > Yes. The caller of this function, drm_dp_dpcd_access(), has the delay > already > > if (ret != 0 && ret != -ETIMEDOUT) { > usleep_range(AUX_RETRY_INTERVAL, > AUX_RETRY_INTERVAL + 100); > } > > so this delay here is redundant. yes, you are right. This is enough.
On 2021-05-07 14:25, Stephen Boyd wrote: > Let's look at the irq status bits after a transfer and see if we got a > nack or a defer or a timeout, instead of telling drm layers that > everything was fine, while still printing an error message. I wasn't > sure about NACK+DEFER so I lumped all those various errors along with a > nack so that the drm core can figure out that things are just not going > well. The important thing is that we're now returning -ETIMEDOUT when > the message times out and nacks for bad addresses. > > Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Cc: Abhinav Kumar <abhinavk@codeaurora.org> > Cc: Kuogee Hsieh <khsieh@codeaurora.org> > Cc: aravindh@codeaurora.org > Cc: Sean Paul <sean@poorly.run> > Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Kuogee Hsieh <khsieh@codeaurora.org> > --- > drivers/gpu/drm/msm/dp/dp_aux.c | 140 ++++++++++++++------------------ > drivers/gpu/drm/msm/dp/dp_aux.h | 8 -- > 2 files changed, 61 insertions(+), 87 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c > b/drivers/gpu/drm/msm/dp/dp_aux.c > index b49810396513..4a3293b590b0 100644 > --- a/drivers/gpu/drm/msm/dp/dp_aux.c > +++ b/drivers/gpu/drm/msm/dp/dp_aux.c > @@ -9,7 +9,15 @@ > #include "dp_reg.h" > #include "dp_aux.h" > > -#define DP_AUX_ENUM_STR(x) #x > +enum msm_dp_aux_err { > + DP_AUX_ERR_NONE, > + DP_AUX_ERR_ADDR, > + DP_AUX_ERR_TOUT, > + DP_AUX_ERR_NACK, > + DP_AUX_ERR_DEFER, > + DP_AUX_ERR_NACK_DEFER, > + DP_AUX_ERR_PHY, > +}; > > struct dp_aux_private { > struct device *dev; > @@ -18,7 +26,7 @@ struct dp_aux_private { > struct mutex mutex; > struct completion comp; > > - u32 aux_error_num; > + enum msm_dp_aux_err aux_error_num; > u32 retry_cnt; > bool cmd_busy; > bool native; > @@ -33,62 +41,45 @@ struct dp_aux_private { > > #define MAX_AUX_RETRIES 5 > > -static const char *dp_aux_get_error(u32 aux_error) > -{ > - switch (aux_error) { > - case DP_AUX_ERR_NONE: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_NONE); > - case DP_AUX_ERR_ADDR: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_ADDR); > - case DP_AUX_ERR_TOUT: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_TOUT); > - case DP_AUX_ERR_NACK: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_NACK); > - case DP_AUX_ERR_DEFER: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_DEFER); > - case DP_AUX_ERR_NACK_DEFER: > - return DP_AUX_ENUM_STR(DP_AUX_ERR_NACK_DEFER); > - default: > - return "unknown"; > - } > -} > - > -static u32 dp_aux_write(struct dp_aux_private *aux, > +static ssize_t dp_aux_write(struct dp_aux_private *aux, > struct drm_dp_aux_msg *msg) > { > - u32 data[4], reg, len; > + u8 data[4]; > + u32 reg; > + ssize_t len; > u8 *msgdata = msg->buffer; > int const AUX_CMD_FIFO_LEN = 128; > int i = 0; > > if (aux->read) > - len = 4; > + len = 0; > else > - len = msg->size + 4; > + len = msg->size; > > /* > * cmd fifo only has depth of 144 bytes > * limit buf length to 128 bytes here > */ > - if (len > AUX_CMD_FIFO_LEN) { > + if (len > AUX_CMD_FIFO_LEN - 4) { > DRM_ERROR("buf size greater than allowed size of 128 bytes\n"); > - return 0; > + return -EINVAL; > } > > /* Pack cmd and write to HW */ > - data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */ > + data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */ > if (aux->read) > - data[0] |= BIT(4); /* R/W */ > + data[0] |= BIT(4); /* R/W */ > > - data[1] = (msg->address >> 8) & 0xff; /* addr[15:8] */ > - data[2] = msg->address & 0xff; /* addr[7:0] */ > - data[3] = (msg->size - 1) & 0xff; /* len[7:0] */ > + data[1] = msg->address >> 8; /* addr[15:8] */ > + data[2] = msg->address; /* addr[7:0] */ > + data[3] = msg->size - 1; /* len[7:0] */ > > - for (i = 0; i < len; i++) { > + for (i = 0; i < len + 4; i++) { > reg = (i < 4) ? data[i] : msgdata[i - 4]; > + reg <<= DP_AUX_DATA_OFFSET; > + reg &= DP_AUX_DATA_MASK; > + reg |= DP_AUX_DATA_WRITE; > /* index = 0, write */ > - reg = (((reg) << DP_AUX_DATA_OFFSET) > - & DP_AUX_DATA_MASK) | DP_AUX_DATA_WRITE; > if (i == 0) > reg |= DP_AUX_DATA_INDEX_WRITE; > aux->catalog->aux_data = reg; > @@ -116,39 +107,27 @@ static u32 dp_aux_write(struct dp_aux_private > *aux, > return len; > } > > -static int dp_aux_cmd_fifo_tx(struct dp_aux_private *aux, > +static ssize_t dp_aux_cmd_fifo_tx(struct dp_aux_private *aux, > struct drm_dp_aux_msg *msg) > { > - u32 ret, len, timeout; > - int aux_timeout_ms = HZ/4; > + ssize_t ret; > + unsigned long time_left; > > reinit_completion(&aux->comp); > > - len = dp_aux_write(aux, msg); > - if (len == 0) { > - DRM_ERROR("DP AUX write failed\n"); > - return -EINVAL; > - } > + ret = dp_aux_write(aux, msg); > + if (ret < 0) > + return ret; > > - timeout = wait_for_completion_timeout(&aux->comp, aux_timeout_ms); > - if (!timeout) { > - DRM_ERROR("aux %s timeout\n", (aux->read ? "read" : "write")); > + time_left = wait_for_completion_timeout(&aux->comp, > + msecs_to_jiffies(250)); > + if (!time_left) > return -ETIMEDOUT; > - } > - > - if (aux->aux_error_num == DP_AUX_ERR_NONE) { > - ret = len; > - } else { > - DRM_ERROR_RATELIMITED("aux err: %s\n", > - dp_aux_get_error(aux->aux_error_num)); > - > - ret = -EINVAL; > - } > > return ret; > } > > -static void dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, > +static ssize_t dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, > struct drm_dp_aux_msg *msg) > { > u32 data; > @@ -175,9 +154,10 @@ static void dp_aux_cmd_fifo_rx(struct > dp_aux_private *aux, > > actual_i = (data >> DP_AUX_DATA_INDEX_OFFSET) & 0xFF; > if (i != actual_i) > - DRM_ERROR("Index mismatch: expected %d, found %d\n", > - i, actual_i); > + break; > } > + > + return i; > } > > static void dp_aux_native_handler(struct dp_aux_private *aux, u32 isr) > @@ -367,36 +347,38 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux > *dp_aux, > } > > ret = dp_aux_cmd_fifo_tx(aux, msg); > - > if (ret < 0) { > if (aux->native) { > aux->retry_cnt++; > if (!(aux->retry_cnt % MAX_AUX_RETRIES)) > dp_catalog_aux_update_cfg(aux->catalog); > } > - usleep_range(400, 500); /* at least 400us to next try */ > - goto unlock_exit; > - } > - > - if (aux->aux_error_num == DP_AUX_ERR_NONE) { > - if (aux->read) > - dp_aux_cmd_fifo_rx(aux, msg); > - > - msg->reply = aux->native ? > - DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK; > } else { > - /* Reply defer to retry */ > - msg->reply = aux->native ? > - DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER; > + aux->retry_cnt = 0; > + switch (aux->aux_error_num) { > + case DP_AUX_ERR_NONE: > + if (aux->read) > + ret = dp_aux_cmd_fifo_rx(aux, msg); > + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_ACK : > DP_AUX_I2C_REPLY_ACK; > + break; > + case DP_AUX_ERR_DEFER: > + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_DEFER : > DP_AUX_I2C_REPLY_DEFER; > + break; > + case DP_AUX_ERR_PHY: > + case DP_AUX_ERR_ADDR: > + case DP_AUX_ERR_NACK: > + case DP_AUX_ERR_NACK_DEFER: > + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_NACK : > DP_AUX_I2C_REPLY_NACK; > + break; > + case DP_AUX_ERR_TOUT: > + ret = -ETIMEDOUT; > + break; > + } > } > > - /* Return requested size for success or retry */ > - ret = msg->size; > - aux->retry_cnt = 0; > - > -unlock_exit: > aux->cmd_busy = false; > mutex_unlock(&aux->mutex); > + > return ret; > } > > diff --git a/drivers/gpu/drm/msm/dp/dp_aux.h > b/drivers/gpu/drm/msm/dp/dp_aux.h > index f8b8ba919465..0728cc09c9ec 100644 > --- a/drivers/gpu/drm/msm/dp/dp_aux.h > +++ b/drivers/gpu/drm/msm/dp/dp_aux.h > @@ -9,14 +9,6 @@ > #include "dp_catalog.h" > #include <drm/drm_dp_helper.h> > > -#define DP_AUX_ERR_NONE 0 > -#define DP_AUX_ERR_ADDR -1 > -#define DP_AUX_ERR_TOUT -2 > -#define DP_AUX_ERR_NACK -3 > -#define DP_AUX_ERR_DEFER -4 > -#define DP_AUX_ERR_NACK_DEFER -5 > -#define DP_AUX_ERR_PHY -6 > - > int dp_aux_register(struct drm_dp_aux *dp_aux); > void dp_aux_unregister(struct drm_dp_aux *dp_aux); > void dp_aux_isr(struct drm_dp_aux *dp_aux);
diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c index b49810396513..4a3293b590b0 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.c +++ b/drivers/gpu/drm/msm/dp/dp_aux.c @@ -9,7 +9,15 @@ #include "dp_reg.h" #include "dp_aux.h" -#define DP_AUX_ENUM_STR(x) #x +enum msm_dp_aux_err { + DP_AUX_ERR_NONE, + DP_AUX_ERR_ADDR, + DP_AUX_ERR_TOUT, + DP_AUX_ERR_NACK, + DP_AUX_ERR_DEFER, + DP_AUX_ERR_NACK_DEFER, + DP_AUX_ERR_PHY, +}; struct dp_aux_private { struct device *dev; @@ -18,7 +26,7 @@ struct dp_aux_private { struct mutex mutex; struct completion comp; - u32 aux_error_num; + enum msm_dp_aux_err aux_error_num; u32 retry_cnt; bool cmd_busy; bool native; @@ -33,62 +41,45 @@ struct dp_aux_private { #define MAX_AUX_RETRIES 5 -static const char *dp_aux_get_error(u32 aux_error) -{ - switch (aux_error) { - case DP_AUX_ERR_NONE: - return DP_AUX_ENUM_STR(DP_AUX_ERR_NONE); - case DP_AUX_ERR_ADDR: - return DP_AUX_ENUM_STR(DP_AUX_ERR_ADDR); - case DP_AUX_ERR_TOUT: - return DP_AUX_ENUM_STR(DP_AUX_ERR_TOUT); - case DP_AUX_ERR_NACK: - return DP_AUX_ENUM_STR(DP_AUX_ERR_NACK); - case DP_AUX_ERR_DEFER: - return DP_AUX_ENUM_STR(DP_AUX_ERR_DEFER); - case DP_AUX_ERR_NACK_DEFER: - return DP_AUX_ENUM_STR(DP_AUX_ERR_NACK_DEFER); - default: - return "unknown"; - } -} - -static u32 dp_aux_write(struct dp_aux_private *aux, +static ssize_t dp_aux_write(struct dp_aux_private *aux, struct drm_dp_aux_msg *msg) { - u32 data[4], reg, len; + u8 data[4]; + u32 reg; + ssize_t len; u8 *msgdata = msg->buffer; int const AUX_CMD_FIFO_LEN = 128; int i = 0; if (aux->read) - len = 4; + len = 0; else - len = msg->size + 4; + len = msg->size; /* * cmd fifo only has depth of 144 bytes * limit buf length to 128 bytes here */ - if (len > AUX_CMD_FIFO_LEN) { + if (len > AUX_CMD_FIFO_LEN - 4) { DRM_ERROR("buf size greater than allowed size of 128 bytes\n"); - return 0; + return -EINVAL; } /* Pack cmd and write to HW */ - data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */ + data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */ if (aux->read) - data[0] |= BIT(4); /* R/W */ + data[0] |= BIT(4); /* R/W */ - data[1] = (msg->address >> 8) & 0xff; /* addr[15:8] */ - data[2] = msg->address & 0xff; /* addr[7:0] */ - data[3] = (msg->size - 1) & 0xff; /* len[7:0] */ + data[1] = msg->address >> 8; /* addr[15:8] */ + data[2] = msg->address; /* addr[7:0] */ + data[3] = msg->size - 1; /* len[7:0] */ - for (i = 0; i < len; i++) { + for (i = 0; i < len + 4; i++) { reg = (i < 4) ? data[i] : msgdata[i - 4]; + reg <<= DP_AUX_DATA_OFFSET; + reg &= DP_AUX_DATA_MASK; + reg |= DP_AUX_DATA_WRITE; /* index = 0, write */ - reg = (((reg) << DP_AUX_DATA_OFFSET) - & DP_AUX_DATA_MASK) | DP_AUX_DATA_WRITE; if (i == 0) reg |= DP_AUX_DATA_INDEX_WRITE; aux->catalog->aux_data = reg; @@ -116,39 +107,27 @@ static u32 dp_aux_write(struct dp_aux_private *aux, return len; } -static int dp_aux_cmd_fifo_tx(struct dp_aux_private *aux, +static ssize_t dp_aux_cmd_fifo_tx(struct dp_aux_private *aux, struct drm_dp_aux_msg *msg) { - u32 ret, len, timeout; - int aux_timeout_ms = HZ/4; + ssize_t ret; + unsigned long time_left; reinit_completion(&aux->comp); - len = dp_aux_write(aux, msg); - if (len == 0) { - DRM_ERROR("DP AUX write failed\n"); - return -EINVAL; - } + ret = dp_aux_write(aux, msg); + if (ret < 0) + return ret; - timeout = wait_for_completion_timeout(&aux->comp, aux_timeout_ms); - if (!timeout) { - DRM_ERROR("aux %s timeout\n", (aux->read ? "read" : "write")); + time_left = wait_for_completion_timeout(&aux->comp, + msecs_to_jiffies(250)); + if (!time_left) return -ETIMEDOUT; - } - - if (aux->aux_error_num == DP_AUX_ERR_NONE) { - ret = len; - } else { - DRM_ERROR_RATELIMITED("aux err: %s\n", - dp_aux_get_error(aux->aux_error_num)); - - ret = -EINVAL; - } return ret; } -static void dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, +static ssize_t dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, struct drm_dp_aux_msg *msg) { u32 data; @@ -175,9 +154,10 @@ static void dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, actual_i = (data >> DP_AUX_DATA_INDEX_OFFSET) & 0xFF; if (i != actual_i) - DRM_ERROR("Index mismatch: expected %d, found %d\n", - i, actual_i); + break; } + + return i; } static void dp_aux_native_handler(struct dp_aux_private *aux, u32 isr) @@ -367,36 +347,38 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux, } ret = dp_aux_cmd_fifo_tx(aux, msg); - if (ret < 0) { if (aux->native) { aux->retry_cnt++; if (!(aux->retry_cnt % MAX_AUX_RETRIES)) dp_catalog_aux_update_cfg(aux->catalog); } - usleep_range(400, 500); /* at least 400us to next try */ - goto unlock_exit; - } - - if (aux->aux_error_num == DP_AUX_ERR_NONE) { - if (aux->read) - dp_aux_cmd_fifo_rx(aux, msg); - - msg->reply = aux->native ? - DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK; } else { - /* Reply defer to retry */ - msg->reply = aux->native ? - DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER; + aux->retry_cnt = 0; + switch (aux->aux_error_num) { + case DP_AUX_ERR_NONE: + if (aux->read) + ret = dp_aux_cmd_fifo_rx(aux, msg); + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK; + break; + case DP_AUX_ERR_DEFER: + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER; + break; + case DP_AUX_ERR_PHY: + case DP_AUX_ERR_ADDR: + case DP_AUX_ERR_NACK: + case DP_AUX_ERR_NACK_DEFER: + msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_NACK : DP_AUX_I2C_REPLY_NACK; + break; + case DP_AUX_ERR_TOUT: + ret = -ETIMEDOUT; + break; + } } - /* Return requested size for success or retry */ - ret = msg->size; - aux->retry_cnt = 0; - -unlock_exit: aux->cmd_busy = false; mutex_unlock(&aux->mutex); + return ret; } diff --git a/drivers/gpu/drm/msm/dp/dp_aux.h b/drivers/gpu/drm/msm/dp/dp_aux.h index f8b8ba919465..0728cc09c9ec 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.h +++ b/drivers/gpu/drm/msm/dp/dp_aux.h @@ -9,14 +9,6 @@ #include "dp_catalog.h" #include <drm/drm_dp_helper.h> -#define DP_AUX_ERR_NONE 0 -#define DP_AUX_ERR_ADDR -1 -#define DP_AUX_ERR_TOUT -2 -#define DP_AUX_ERR_NACK -3 -#define DP_AUX_ERR_DEFER -4 -#define DP_AUX_ERR_NACK_DEFER -5 -#define DP_AUX_ERR_PHY -6 - int dp_aux_register(struct drm_dp_aux *dp_aux); void dp_aux_unregister(struct drm_dp_aux *dp_aux); void dp_aux_isr(struct drm_dp_aux *dp_aux);
Let's look at the irq status bits after a transfer and see if we got a nack or a defer or a timeout, instead of telling drm layers that everything was fine, while still printing an error message. I wasn't sure about NACK+DEFER so I lumped all those various errors along with a nack so that the drm core can figure out that things are just not going well. The important thing is that we're now returning -ETIMEDOUT when the message times out and nacks for bad addresses. Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Abhinav Kumar <abhinavk@codeaurora.org> Cc: Kuogee Hsieh <khsieh@codeaurora.org> Cc: aravindh@codeaurora.org Cc: Sean Paul <sean@poorly.run> Signed-off-by: Stephen Boyd <swboyd@chromium.org> --- drivers/gpu/drm/msm/dp/dp_aux.c | 140 ++++++++++++++------------------ drivers/gpu/drm/msm/dp/dp_aux.h | 8 -- 2 files changed, 61 insertions(+), 87 deletions(-)