On 07.06.2019 06:45, Andrey Smirnov wrote:
> Don't assume that requested data transfer size is the same as amount
> of data that was transferred. Change the code to get that information
> from DP0_AUXSTATUS instead.
>
> Since the check for AUX_BUSY in tc_aux_get_status() is pointless (it
> will always called after tc_aux_wait_busy()) and there's only one user
> of it, inline its code into tc_aux_transfer() instead of trying to
> accommodate the change above.
>
> Signed-off-by: Andrey Smirnov <andrew.smir...@gmail.com>
Reviewed-by: Andrzej Hajda <a.ha...@samsung.com>
--
Regards
Andrzej
> Cc: Andrzej Hajda <a.ha...@samsung.com>
> Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> Cc: Tomi Valkeinen <tomi.valkei...@ti.com>
> Cc: Andrey Gusakov <andrey.gusa...@cogentembedded.com>
> Cc: Philipp Zabel <p.za...@pengutronix.de>
> Cc: Cory Tusar <cory.tu...@zii.aero>
> Cc: Chris Healy <cphe...@gmail.com>
> Cc: Lucas Stach <l.st...@pengutronix.de>
> Cc: dri-de...@lists.freedesktop.org
> Cc: linux-kernel@vger.kernel.org
> ---
> drivers/gpu/drm/bridge/tc358767.c | 40 ++++++++++---------------------
> 1 file changed, 12 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358767.c
> b/drivers/gpu/drm/bridge/tc358767.c
> index 8b53dc8908d3..7d0fbb12195b 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -152,10 +152,10 @@
> #define DP0_AUXWDATA(i) (0x066c + (i) * 4)
> #define DP0_AUXRDATA(i) (0x067c + (i) * 4)
> #define DP0_AUXSTATUS 0x068c
> -#define AUX_STATUS_MASK 0xf0
> -#define AUX_STATUS_SHIFT 4
> -#define AUX_TIMEOUT BIT(1)
> -#define AUX_BUSY BIT(0)
> +#define AUX_BYTES GENMASK(15, 8)
> +#define AUX_STATUS GENMASK(7, 4)
> +#define AUX_TIMEOUT BIT(1)
> +#define AUX_BUSY BIT(0)
> #define DP0_AUXI2CADR 0x0698
>
> /* Link Training */
> @@ -298,29 +298,6 @@ static int tc_aux_wait_busy(struct tc_data *tc, unsigned
> int timeout_ms)
> 1000, 1000 * timeout_ms);
> }
>
> -static int tc_aux_get_status(struct tc_data *tc, u8 *reply)
> -{
> - int ret;
> - u32 value;
> -
> - ret = regmap_read(tc->regmap, DP0_AUXSTATUS, &value);
> - if (ret < 0)
> - return ret;
> -
> - if (value & AUX_BUSY) {
> - dev_err(tc->dev, "aux busy!\n");
> - return -EBUSY;
> - }
> -
> - if (value & AUX_TIMEOUT) {
> - dev_err(tc->dev, "aux access timeout!\n");
> - return -ETIMEDOUT;
> - }
> -
> - *reply = (value & AUX_STATUS_MASK) >> AUX_STATUS_SHIFT;
> - return 0;
> -}
> -
> static int tc_aux_write_data(struct tc_data *tc, const void *data,
> size_t size)
> {
> @@ -356,6 +333,7 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
> struct tc_data *tc = aux_to_tc(aux);
> size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size);
> u8 request = msg->request & ~DP_AUX_I2C_MOT;
> + u32 auxstatus;
> int ret;
>
> if (size == 0)
> @@ -393,10 +371,16 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
> if (ret)
> return ret;
>
> - ret = tc_aux_get_status(tc, &msg->reply);
> + ret = regmap_read(tc->regmap, DP0_AUXSTATUS, &auxstatus);
> if (ret)
> return ret;
>
> + if (auxstatus & AUX_TIMEOUT)
> + return -ETIMEDOUT;
> +
> + size = FIELD_GET(AUX_BYTES, auxstatus);
> + msg->reply = FIELD_GET(AUX_STATUS, auxstatus);
> +
> switch (request) {
> case DP_AUX_NATIVE_READ:
> case DP_AUX_I2C_READ:
