From 2f221a5efed4cb369dc53cbbae3ba03fcf2ede49 Mon Sep 17 00:00:00 2001 From: David Francis Date: Wed, 19 Jun 2019 14:46:15 -0400 Subject: [PATCH] drm/dp_mst: Add MST support to DP DPCD R/W functions Instead of having drm_dp_dpcd_read/write and drm_dp_mst_dpcd_read/write as entry points into the aux code, have drm_dp_dpcd_read/write handle both. This means that DRM drivers can make MST DPCD read/writes. v2: Fix spacing v3: Dump dpcd access on MST read/writes v4: Fix calling wrong function on DPCD write v5: delete deprecated include of drmP.h Reviewed-by: Lyude Paul Reviewed-by: Harry Wentland Signed-off-by: David Francis Signed-off-by: Mikita Lipski Signed-off-by: Alex Deucher --- drivers/gpu/drm/drm_dp_aux_dev.c | 12 ++---------- drivers/gpu/drm/drm_dp_helper.c | 30 ++++++++++++++++++++---------- 2 files changed, 22 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c b/drivers/gpu/drm/drm_dp_aux_dev.c index 0cfb386754c3..2510717d5a08 100644 --- a/drivers/gpu/drm/drm_dp_aux_dev.c +++ b/drivers/gpu/drm/drm_dp_aux_dev.c @@ -163,11 +163,7 @@ static ssize_t auxdev_read_iter(struct kiocb *iocb, struct iov_iter *to) break; } - if (aux_dev->aux->is_remote) - res = drm_dp_mst_dpcd_read(aux_dev->aux, pos, buf, - todo); - else - res = drm_dp_dpcd_read(aux_dev->aux, pos, buf, todo); + res = drm_dp_dpcd_read(aux_dev->aux, pos, buf, todo); if (res <= 0) break; @@ -215,11 +211,7 @@ static ssize_t auxdev_write_iter(struct kiocb *iocb, struct iov_iter *from) break; } - if (aux_dev->aux->is_remote) - res = drm_dp_mst_dpcd_write(aux_dev->aux, pos, buf, - todo); - else - res = drm_dp_dpcd_write(aux_dev->aux, pos, buf, todo); + res = drm_dp_dpcd_write(aux_dev->aux, pos, buf, todo); if (res <= 0) break; diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 2c7870aef469..2faef8bd911f 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -32,6 +32,7 @@ #include #include #include +#include #include "drm_crtc_helper_internal.h" @@ -266,7 +267,7 @@ unlock: /** * drm_dp_dpcd_read() - read a series of bytes from the DPCD - * @aux: DisplayPort AUX channel + * @aux: DisplayPort AUX channel (SST or MST) * @offset: address of the (first) register to read * @buffer: buffer to store the register values * @size: number of bytes in @buffer @@ -295,13 +296,18 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, * We just have to do it before any DPCD access and hope that the * monitor doesn't power down exactly after the throw away read. */ - ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer, - 1); - if (ret != 1) - goto out; + if (!aux->is_remote) { + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, + buffer, 1); + if (ret != 1) + goto out; + } - ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer, - size); + if (aux->is_remote) + ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size); + else + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, + buffer, size); out: drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret); @@ -311,7 +317,7 @@ EXPORT_SYMBOL(drm_dp_dpcd_read); /** * drm_dp_dpcd_write() - write a series of bytes to the DPCD - * @aux: DisplayPort AUX channel + * @aux: DisplayPort AUX channel (SST or MST) * @offset: address of the (first) register to write * @buffer: buffer containing the values to write * @size: number of bytes in @buffer @@ -328,8 +334,12 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, { int ret; - ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, - size); + if (aux->is_remote) + ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size); + else + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, + buffer, size); + drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret); return ret; } -- 2.34.1