From 5a5efbf4ef504a8136963a8ae10a3c0a1d59b479 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 19 Jun 2019 21:03:07 +0300 Subject: [PATCH] drm/i915/sdvo: Fix handling if zero hbuf size MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The spec says: "A value of 0 indicates that this buffer does not exist" So we should not convert a hbuf_size of 0 into 1. Also pull the relevant code into a helper to avoid making the same mistake multiple times. And while at it fix the debug prints to not say "hbuf_len" twice. v2: s/%i/%u/ in the debug (Imre) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20190619180312.31817-1-ville.syrjala@linux.intel.com Reviewed-by: Imre Deak --- drivers/gpu/drm/i915/display/intel_sdvo.c | 32 ++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c b/drivers/gpu/drm/i915/display/intel_sdvo.c index 3fe8eaef6bd8..213843a93c4e 100644 --- a/drivers/gpu/drm/i915/display/intel_sdvo.c +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c @@ -951,6 +951,20 @@ static bool intel_sdvo_set_audio_state(struct intel_sdvo *intel_sdvo, &audio_state, 1); } +static bool intel_sdvo_get_hbuf_size(struct intel_sdvo *intel_sdvo, + u8 *hbuf_size) +{ + if (!intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_HBUF_INFO, + hbuf_size, 1)) + return false; + + /* Buffer size is 0 based, hooray! However zero means zero. */ + if (*hbuf_size) + (*hbuf_size)++; + + return true; +} + #if 0 static void intel_sdvo_dump_hdmi_buf(struct intel_sdvo *intel_sdvo) { @@ -994,14 +1008,10 @@ static bool intel_sdvo_write_infoframe(struct intel_sdvo *intel_sdvo, set_buf_index, 2)) return false; - if (!intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_HBUF_INFO, - &hbuf_size, 1)) + if (!intel_sdvo_get_hbuf_size(intel_sdvo, &hbuf_size)) return false; - /* Buffer size is 0 based, hooray! */ - hbuf_size++; - - DRM_DEBUG_KMS("writing sdvo hbuf: %i, hbuf_size %i, hbuf_size: %i\n", + DRM_DEBUG_KMS("writing sdvo hbuf: %i, length %u, hbuf_size: %i\n", if_index, length, hbuf_size); if (hbuf_size < length) @@ -1052,14 +1062,10 @@ static ssize_t intel_sdvo_read_infoframe(struct intel_sdvo *intel_sdvo, if (tx_rate == SDVO_HBUF_TX_DISABLED) return 0; - if (!intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_HBUF_INFO, - &hbuf_size, 1)) - return -ENXIO; - - /* Buffer size is 0 based, hooray! */ - hbuf_size++; + if (!intel_sdvo_get_hbuf_size(intel_sdvo, &hbuf_size)) + return false; - DRM_DEBUG_KMS("reading sdvo hbuf: %i, hbuf_size %i, hbuf_size: %i\n", + DRM_DEBUG_KMS("reading sdvo hbuf: %i, length %u, hbuf_size: %i\n", if_index, length, hbuf_size); hbuf_size = min_t(unsigned int, length, hbuf_size); -- 2.11.0