[PATCH v3 10/16] drm/dp-mst: Add MST support to DP DPCD R/W functions
Lyude Paul
lyude at redhat.com
Wed Aug 21 21:08:29 UTC 2019
On Wed, 2019-08-21 at 16:01 -0400, David Francis wrote:
> 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.
>
> Cc: Leo Li <sunpeng.li at amd.com>
> Cc: Lyude Paul <lyude at redhat.com>
> Signed-off-by: David Francis <David.Francis at amd.com>
> ---
> drivers/gpu/drm/drm_dp_aux_dev.c | 12 ++----------
> drivers/gpu/drm/drm_dp_helper.c | 10 ++++++++--
> 2 files changed, 10 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c
> b/drivers/gpu/drm/drm_dp_aux_dev.c
> index 00610bd8d6c1..0780fc358389 100644
> --- a/drivers/gpu/drm/drm_dp_aux_dev.c
> +++ b/drivers/gpu/drm/drm_dp_aux_dev.c
> @@ -162,11 +162,7 @@ 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;
> @@ -214,11 +210,7 @@ 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_mst_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 54a6414c5d96..9f976b90c53a 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -29,6 +29,7 @@
> #include <linux/i2c.h>
> #include <linux/seq_file.h>
> #include <drm/drm_dp_helper.h>
> +#include <drm/drm_dp_mst_helper.h>
> #include <drm/drmP.h>
>
> #include "drm_crtc_helper_internal.h"
> @@ -272,7 +273,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8
> request,
>
> /**
> * 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
> @@ -289,6 +290,8 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux,
> unsigned int offset,
> {
> int ret;
>
> + if (aux->is_remote)
> + return drm_dp_mst_dpcd_read(aux, offset, buffer, size);
Please follow the kernel style guidelines. We indent with tabs first, not
spaces.
> /*
> * HP ZR24w corrupts the first DPCD access after entering power save
> * mode. Eg. on a read, the entire buffer will be filled with the same
> @@ -317,7 +320,7 @@ 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
> @@ -334,6 +337,9 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux,
> unsigned int offset,
> {
> int ret;
>
> + if (aux->is_remote)
> + return drm_dp_mst_dpcd_write(aux, offset, buffer, size);
> +
Same here
> 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);
--
Cheers,
Lyude Paul
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