diff options
| author |   Thierry Reding <treding@nvidia.com> | 2016-03-03 15:32:13 +0100 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2019-10-28 11:18:43 +0100 |
| commit | 245ce70cd466d2e003861788d13726417557eb39 (patch) | |
| tree | a119b709d5f4c91f9de50e5550612d4580463939 /drivers/gpu/drm/tegra/dpaux.c | |
| parent | drm/tegra: dpaux: Support monitor hotplugging (diff) | |
| download | linux-dev-245ce70cd466d2e003861788d13726417557eb39.tar.xz linux-dev-245ce70cd466d2e003861788d13726417557eb39.zip | |
drm/tegra: dpaux: Retry on transfer size mismatch
When a transfer didn't complete transmission of the requested number of
bytes, signal that the transaction should be retried.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/drm/tegra/dpaux.c')
| -rw-r--r-- | drivers/gpu/drm/tegra/dpaux.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c index 4a35a6e0e2aa..819fdd9b4413 100644 --- a/drivers/gpu/drm/tegra/dpaux.c +++ b/drivers/gpu/drm/tegra/dpaux.c @@ -121,6 +121,7 @@ static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux, struct tegra_dpaux *dpaux = to_dpaux(aux); unsigned long status; ssize_t ret = 0; + u8 reply = 0; u32 value; /* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */ @@ -215,23 +216,23 @@ static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux, switch ((value & DPAUX_DP_AUXSTAT_REPLY_TYPE_MASK) >> 16) { case 0x00: - msg->reply = DP_AUX_NATIVE_REPLY_ACK; + reply = DP_AUX_NATIVE_REPLY_ACK; break; case 0x01: - msg->reply = DP_AUX_NATIVE_REPLY_NACK; + reply = DP_AUX_NATIVE_REPLY_NACK; break; case 0x02: - msg->reply = DP_AUX_NATIVE_REPLY_DEFER; + reply = DP_AUX_NATIVE_REPLY_DEFER; break; case 0x04: - msg->reply = DP_AUX_I2C_REPLY_NACK; + reply = DP_AUX_I2C_REPLY_NACK; break; case 0x08: - msg->reply = DP_AUX_I2C_REPLY_DEFER; + reply = DP_AUX_I2C_REPLY_DEFER; break; } @@ -239,14 +240,24 @@ static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux, if (msg->request & DP_AUX_I2C_READ) { size_t count = value & DPAUX_DP_AUXSTAT_REPLY_MASK; - if (WARN_ON(count != msg->size)) - count = min_t(size_t, count, msg->size); + /* + * There might be a smarter way to do this, but since + * the DP helpers will already retry transactions for + * an -EBUSY return value, simply reuse that instead. + */ + if (count != msg->size) { + ret = -EBUSY; + goto out; + } tegra_dpaux_read_fifo(dpaux, msg->buffer, count); ret = count; } } + msg->reply = reply; + +out: return ret; } |