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Date: Thu, 23 Jun 2011 18:55:18 -0400
From: Alex Deucher <alexdeucher@...il.com>
To: reimth@...glemail.com
Cc: Dave Airlie <airlied@...hat.com>,
Mario Kleiner <mario.kleiner@...bingen.mpg.de>,
Jean Delvare <khali@...ux-fr.org>,
Tyson Whitehead <twhitehead@...il.com>,
Jason Wessel <jason.wessel@...driver.com>,
dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
Thomas Reim <rdratlos@...oo.co.uk>
Subject: Re: [PATCH] drm/radeon: Fix Asus M2A-VM HDMI EDID error flooding problem
On Thu, Jun 23, 2011 at 6:05 PM, <reimth@...glemail.com> wrote:
> From: Thomas Reim <rdratlos@...oo.co.uk>
>
> Some integrated ATI Radeon chipset implementations
> (e. g. Asus M2A-VM HDMI, RS690) indicate the availability
> of a DDC even when there's no monitor connected.
> In this case, drm_get_edid() and drm_edid_block_valid()
> periodically dump data and kernel errors into system
> log files and onto terminals, which lead to an unacceptable
> system behaviour. For this purpose function drm_edid_header_is_valid()
> has been added to drm and function drm_edid_block_valid()
> has been adapted to also use drm_edid_header_is_valid().
>
> Tested since kernel 2.35 on Asus M2A-VM HDMI board
See comments below.
Alex
>
> Signed-off-by: Thomas Reim <rdratlos@...oo.co.uk>
> ---
> drivers/gpu/drm/drm_edid.c | 23 +++++++++++---
> drivers/gpu/drm/radeon/radeon_connectors.c | 29 ++++++++++++++++-
> drivers/gpu/drm/radeon/radeon_display.c | 12 +++++++
> drivers/gpu/drm/radeon/radeon_i2c.c | 45 ++++++++++++++++++++++++++-
> drivers/gpu/drm/radeon/radeon_mode.h | 4 ++
> include/drm/drm_crtc.h | 1 +
> 6 files changed, 105 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 0929219..1daaf81 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -128,6 +128,23 @@ static const u8 edid_header[] = {
> };
>
> /*
> + * Sanity check the header of the base EDID block. Return 8 if the header
> + * is perfect, down to 0 if it's totally wrong.
> + */
> +int drm_edid_header_is_valid(const u8 *raw_edid)
> +{
> + int i, score = 0;
> +
> + for (i = 0; i < sizeof(edid_header); i++)
> + if (raw_edid[i] == edid_header[i])
> + score++;
> +
> + return score;
> +}
> +EXPORT_SYMBOL(drm_edid_header_is_valid);
> +
> +
> +/*
> * Sanity check the EDID block (base or extension). Return 0 if the block
> * doesn't check out, or 1 if it's valid.
> */
> @@ -139,11 +156,7 @@ drm_edid_block_valid(u8 *raw_edid)
> struct edid *edid = (struct edid *)raw_edid;
>
> if (raw_edid[0] == 0x00) {
> - int score = 0;
> -
> - for (i = 0; i < sizeof(edid_header); i++)
> - if (raw_edid[i] == edid_header[i])
> - score++;
> + int score = drm_edid_header_is_valid(raw_edid);
>
> if (score == 8) ;
> else if (score >= 6) {
> diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
> index cbfca3a..bcd2380 100644
> --- a/drivers/gpu/drm/radeon/radeon_connectors.c
> +++ b/drivers/gpu/drm/radeon/radeon_connectors.c
> @@ -826,8 +826,12 @@ radeon_dvi_detect(struct drm_connector *connector, bool force)
> enum drm_connector_status ret = connector_status_disconnected;
> bool dret = false;
>
> - if (radeon_connector->ddc_bus)
> - dret = radeon_ddc_probe(radeon_connector);
> + if (radeon_connector->ddc_bus) {
> + if (radeon_connector->requires_extended_probe)
> + dret = radeon_ddc_probe_extended(radeon_connector);
> + else
> + dret = radeon_ddc_probe(radeon_connector);
> + }
Thinking about it more, it might be cleaner to just make the extended
mode a flag, e.g.,
dret = radeon_ddc_probe_extended(radeon_connector,
radeon_connector->requires_extended_probe);
and handle the extended fetch in the same probe function.
> if (dret) {
> if (radeon_connector->edid) {
> kfree(radeon_connector->edid);
> @@ -1342,6 +1346,7 @@ radeon_add_atom_connector(struct drm_device *dev,
> struct radeon_encoder *radeon_encoder;
> uint32_t subpixel_order = SubPixelNone;
> bool shared_ddc = false;
> + bool requires_extended_probe = false;
> bool is_dp_bridge = false;
>
> if (connector_type == DRM_MODE_CONNECTOR_Unknown)
> @@ -1400,6 +1405,7 @@ radeon_add_atom_connector(struct drm_device *dev,
> radeon_connector->shared_ddc = shared_ddc;
> radeon_connector->connector_object_id = connector_object_id;
> radeon_connector->hpd = *hpd;
> + radeon_connector->requires_extended_probe = requires_extended_probe;
> radeon_connector->router = *router;
> if (router->ddc_valid || router->cd_valid) {
> radeon_connector->router_bus = radeon_i2c_lookup(rdev, &router->i2c_info);
> @@ -1688,6 +1694,23 @@ radeon_add_atom_connector(struct drm_device *dev,
> }
> }
>
> + /* RS690 HDMI DDC quirk:
> + * Some integrated ATI Radeon chipset implementations (e. g.
> + * Asus M2A-VM HDMI) indicate the availability of a DDC even
> + * when there's no monitor connected to HDMI. For HDMI
> + * connectors we check for the availability of EDID with
> + * at least a correct EDID header and EDID version/revision
> + * information. Only then, DDC is assumed to be available.
> + * This prevents drm_get_edid() and drm_edid_block_valid() of
> + * periodically dumping data and kernel errors into the logs
> + * and onto the terminal, which would lead to an unacceptable
> + * system behaviour */
> + if (connector_type == DRM_MODE_CONNECTOR_HDMIA &&
> + (rdev->family == CHIP_RS690 ||
> + rdev->family == CHIP_RS740 ||
> + rdev->family == CHIP_RV630))
This seems like an arbitrary selection of chips. I haven't heard of
any problems related to ddc on rv630. Also I think we should limit it
to the specific connector that is problematic rather than all hdmi
ports. In the case of your board, it seems the hdmi port on the
add-in card is the only problematic one. Lots of rs690 motherboards
have hdmi ports on the motherboard itself that work fine. I'd prefer
to match based on the pci device and subsytem ids and the
supported_device and connector type. See radeon_atom_apply_quirks()
in radeon_atombios.c for an example. Something like:
radeon_connector->requires_extended_probe =
radeon_connector_needs_extended_probe(rdev, supported_dev,
connector_type);
> + requires_extended_probe = true;
> + radeon_connector->requires_extended_probe = requires_extended_probe;
> if (radeon_connector->hpd.hpd == RADEON_HPD_NONE) {
> if (i2c_bus->valid)
> connector->polled = DRM_CONNECTOR_POLL_CONNECT;
> @@ -1716,6 +1739,7 @@ radeon_add_legacy_connector(struct drm_device *dev,
> struct drm_connector *connector;
> struct radeon_connector *radeon_connector;
> uint32_t subpixel_order = SubPixelNone;
> + bool requires_extended_probe = false;
>
> if (connector_type == DRM_MODE_CONNECTOR_Unknown)
> return;
> @@ -1746,6 +1770,7 @@ radeon_add_legacy_connector(struct drm_device *dev,
> radeon_connector->devices = supported_device;
> radeon_connector->connector_object_id = connector_object_id;
> radeon_connector->hpd = *hpd;
> + radeon_connector->requires_extended_probe = requires_extended_probe;
> switch (connector_type) {
> case DRM_MODE_CONNECTOR_VGA:
> drm_connector_init(dev, &radeon_connector->base, &radeon_vga_connector_funcs, connector_type);
> diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
> index 292f73f..27e6840 100644
> --- a/drivers/gpu/drm/radeon/radeon_display.c
> +++ b/drivers/gpu/drm/radeon/radeon_display.c
> @@ -715,6 +715,9 @@ static bool radeon_setup_enc_conn(struct drm_device *dev)
> if (ret) {
> radeon_setup_encoder_clones(dev);
> radeon_print_display_setup(dev);
> + /* Is this really required here?
> + Seems to just force drm to dump EDID errors
> + to kernel logs */
> list_for_each_entry(drm_connector, &dev->mode_config.connector_list, head)
> radeon_ddc_dump(drm_connector);
Both the code and the comment can probably be removed, but let's make
that a separate patch.
> }
> @@ -777,8 +780,17 @@ static int radeon_ddc_dump(struct drm_connector *connector)
> if (!radeon_connector->ddc_bus)
> return -1;
> edid = drm_get_edid(connector, &radeon_connector->ddc_bus->adapter);
> + /* Log EDID retrieval status here. In particular with regard to
> + * connectors with requires_extended_probe flag set, that will prevent
> + * function radeon_dvi_detect() to fetch EDID on this connector,
> + * as long as there is no valid EDID header found */
> if (edid) {
> + DRM_INFO("Radeon display connector %s: Found valid EDID",
> + drm_get_connector_name(connector));
> kfree(edid);
> + } else {
> + DRM_INFO("Radeon display connector %s: No monitor connected or invalid EDID",
> + drm_get_connector_name(connector));
These will just spam the log as well.
> }
> return ret;
> }
> diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
> index 781196d..7e93cf9 100644
> --- a/drivers/gpu/drm/radeon/radeon_i2c.c
> +++ b/drivers/gpu/drm/radeon/radeon_i2c.c
> @@ -34,7 +34,7 @@
> */
> bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
> {
> - u8 out_buf[] = { 0x0, 0x0};
> + u8 out = 0x0;
> u8 buf[2];
> int ret;
> struct i2c_msg msgs[] = {
> @@ -42,7 +42,7 @@ bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
> .addr = 0x50,
> .flags = 0,
> .len = 1,
> - .buf = out_buf,
> + .buf = &out,
> },
> {
> .addr = 0x50,
The change above doesn't seem to be related.
> @@ -63,6 +63,47 @@ bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
> return false;
> }
>
> +/*
> + * Probe EDID header information via I2C:
> + * Try to fetch EDID information by calling i2c_transfer driver function and
> + * probe for a valid EDID header
> + */
> +bool radeon_ddc_probe_extended(struct radeon_connector *radeon_connector)
> +{
> + u8 out = 0x0;
> + u8 block[8];
> + int ret;
> + struct i2c_msg msgs[] = {
> + {
> + .addr = 0x50,
> + .flags = 0,
> + .len = 1,
> + .buf = &out,
> + }, {
> + .addr = 0x50,
> + .flags = I2C_M_RD,
> + .len = 8,
> + .buf = block,
> + }
> + };
> +
> + /* on hw with routers, select right port */
> + if (radeon_connector->router.ddc_valid)
> + radeon_router_select_ddc_port(radeon_connector);
> +
> + ret = i2c_transfer(&radeon_connector->ddc_bus->adapter, msgs, 2);
> + if (ret == 2)
> + if (drm_edid_header_is_valid(block) >= 6)
> + /* EDID header starts with:
> + * 0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00
> + * Only the first 6 bytes must be valid as
> + * drm_edid_block_valid() can fix the last 2 bytes
> + */
> + return true;
> + /* Couldn't find an accessible EDID on this connector */
> + return false;
> +}
> +
> /* bit banging i2c */
>
> static void radeon_i2c_do_lock(struct radeon_i2c_chan *i2c, int lock_state)
> diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
> index 6df4e3c..b834f27 100644
> --- a/drivers/gpu/drm/radeon/radeon_mode.h
> +++ b/drivers/gpu/drm/radeon/radeon_mode.h
> @@ -438,6 +438,9 @@ struct radeon_connector {
> struct radeon_i2c_chan *ddc_bus;
> /* some systems have an hdmi and vga port with a shared ddc line */
> bool shared_ddc;
> + /* for some Radeon chip families we apply an additional EDID header
> + check as part of the DDC probe */
> + bool requires_extended_probe;
> bool use_digital;
> /* we need to mind the EDID between detect
> and get modes due to analog/digital/tvencoder */
> @@ -515,6 +518,7 @@ extern void radeon_i2c_put_byte(struct radeon_i2c_chan *i2c,
> extern void radeon_router_select_ddc_port(struct radeon_connector *radeon_connector);
> extern void radeon_router_select_cd_port(struct radeon_connector *radeon_connector);
> extern bool radeon_ddc_probe(struct radeon_connector *radeon_connector);
> +extern bool radeon_ddc_probe_extended(struct radeon_connector *radeon_connector);
> extern int radeon_ddc_get_modes(struct radeon_connector *radeon_connector);
>
> extern struct drm_encoder *radeon_best_encoder(struct drm_connector *connector);
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 33d12f8..0ec3687 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -802,6 +802,7 @@ extern struct drm_display_mode *drm_gtf_mode_complex(struct drm_device *dev,
> extern int drm_add_modes_noedid(struct drm_connector *connector,
> int hdisplay, int vdisplay);
>
> +extern int drm_edid_header_is_valid(const u8 *raw_edid);
> extern bool drm_edid_is_valid(struct edid *edid);
> struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
> int hsize, int vsize, int fresh);
> --
> 1.7.1
>
>
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