On 2019-11-25 4:36 p.m., Zuo, Jerry wrote:
> Please kindly give a review on my latest revision. Thanks a lot.
>
Both patches are
Reviewed-by: Harry Wentland <harry.wentl...@amd.com>
Harry
> Regards,
> Jerry
>
> -----Original Message-----
> From: Jerry (Fangzhi) Zuo <jerry....@amd.com>
> Sent: November 5, 2019 11:38 AM
> To: dri-devel@lists.freedesktop.org; amd-...@lists.freedesktop.org
> Cc: ly...@redhat.com; manasi.d.nav...@intel.com; Wentland, Harry
> <harry.wentl...@amd.com>; Zuo, Jerry <jerry....@amd.com>
> Subject: [PATCH v4] drm: Add support for DP 1.4 Compliance edid corruption
> test 4.2.2.6
>
> DP 1.4 edid corruption test requires source DUT to write calculated CRC, not
> the corrupted CRC from reference sink.
>
> Return the calculated CRC back, and initiate the required sequence.
>
> -v2: Have separate routine for returning real CRC
>
> -v3: Rewrite checksum computation routine to avoid duplicated code.
> Rename to avoid confusion
>
> -v4: Fix a minor typo.
>
> Signed-off-by: Jerry (Fangzhi) Zuo <jerry....@amd.com>
> ---
> drivers/gpu/drm/drm_dp_helper.c | 36 ++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/drm_edid.c | 18 +++++++++++++++---
> include/drm/drm_connector.h | 7 +++++++
> include/drm/drm_dp_helper.h | 3 +++
> 4 files changed, 61 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c
> b/drivers/gpu/drm/drm_dp_helper.c index ffc68d305afe..22a0e966ea9f 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -336,6 +336,42 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
> } EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
>
> +/**
> + * drm_dp_send_real_edid_checksum() - send back real edid checksum
> +value
> + * @aux: DisplayPort AUX channel
> + * @real_edid_checksum: real edid checksum for the last block
> + *
> + * Returns true on success
> + */
> +bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
> + u8 real_edid_checksum) {
> + u8 link_edid_read = 0, auto_test_req = 0;
> + u8 test_resp = 0;
> +
> + drm_dp_dpcd_read(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, &auto_test_req,
> 1);
> + auto_test_req &= DP_AUTOMATED_TEST_REQUEST;
> +
> + drm_dp_dpcd_read(aux, DP_TEST_REQUEST, &link_edid_read, 1);
> + link_edid_read &= DP_TEST_LINK_EDID_READ;
> +
> + if (!auto_test_req || !link_edid_read) {
> + DRM_DEBUG_KMS("Source DUT does not support
> TEST_EDID_READ\n");
> + return false;
> + }
> +
> + drm_dp_dpcd_write(aux, DP_DEVICE_SERVICE_IRQ_VECTOR,
> + &auto_test_req, 1);
> +
> + /* send back checksum for the last edid extension block data */
> + drm_dp_dpcd_write(aux, DP_TEST_EDID_CHECKSUM,
> + &real_edid_checksum, 1);
> +
> + test_resp |= DP_TEST_EDID_CHECKSUM_WRITE;
> + drm_dp_dpcd_write(aux, DP_TEST_RESPONSE, &test_resp, 1);
> +
> + return true;
> +}
> +EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
> +
> /**
> * drm_dp_link_probe() - probe a DisplayPort link for capabilities
> * @aux: DisplayPort AUX channel
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index
> 82a4ceed3fcf..ff64e5f1feb6 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1348,10 +1348,19 @@ static int drm_edid_block_checksum(const u8
> *raw_edid) {
> int i;
> u8 csum = 0;
> - for (i = 0; i < EDID_LENGTH; i++)
> +
> + for (i = 0; i < EDID_LENGTH - 1; i++)
> csum += raw_edid[i];
>
> - return csum;
> + return (0x100 - csum);
> +}
> +
> +static bool drm_edid_block_checksum_diff(const u8 *raw_edid, u8
> +real_checksum) {
> + if (raw_edid[EDID_LENGTH - 1] != real_checksum)
> + return true;
> + else
> + return false;
> }
>
> static bool drm_edid_is_zero(const u8 *in_edid, int length) @@ -1409,7
> +1418,7 @@ bool drm_edid_block_valid(u8 *raw_edid, int block, bool
> print_bad_edid,
> }
>
> csum = drm_edid_block_checksum(raw_edid);
> - if (csum) {
> + if (drm_edid_block_checksum_diff(raw_edid, csum)) {
> if (edid_corrupt)
> *edid_corrupt = true;
>
> @@ -1572,6 +1581,9 @@ static void connector_bad_edid(struct drm_connector
> *connector,
> prefix, DUMP_PREFIX_NONE, 16, 1,
> block, EDID_LENGTH, false);
> }
> +
> + /* Calculate real checksum for the last edid extension block data */
> + connector->real_edid_checksum = drm_edid_block_checksum(edid +
> +edid[0x7e] * EDID_LENGTH);
> }
>
> /* Get override or firmware EDID */
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index
> 681cb590f952..eb0d8c7b35fd 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1345,6 +1345,13 @@ struct drm_connector {
> * rev1.1 4.2.2.6
> */
> bool edid_corrupt;
> + /**
> + * @real_edid_checksum: real edid checksum value for corrupted edid
> block.
> + * Required in Displayport 1.4 compliance testing
> + * rev1.1 4.2.2.6
> + */
> + uint8_t real_edid_checksum;
> +
>
> /** @debugfs_entry: debugfs directory for this connector */
> struct dentry *debugfs_entry;
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index
> 5a795075d5da..84709d7810f8 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -1383,6 +1383,9 @@ static inline ssize_t drm_dp_dpcd_writeb(struct
> drm_dp_aux *aux, int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
> u8 status[DP_LINK_STATUS_SIZE]);
>
> +bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
> + u8 real_edid_checksum);
> +
> /*
> * DisplayPort link
> */
> --
> 2.14.1
>
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