[PATCH v5 2/3] winex11.drv: Add EDID to the virtual desktop monitor device.

[Zhiyi Zhang]

On 9/11/21 12:28 AM, Eduard Permyakov wrote:
>
> On 2021-09-08 6:42 p.m., Zhiyi Zhang wrote:
>>
>> On 9/8/21 1:43 AM, Eduard Permyakov wrote:
>>> Some applications use the EDID property of the monitor device
>>> to detect supported resolutions, and set the viewport size. Add
>>> a computed EDID to the virtual desktop monitor device to allow
>>> the virtual desktop driver to be better compatible with such
>>> applications.
>>>
>>> Most fields of the EDID contain details that are of no relevance
>>> to applications, so populate only the native resolution and physical
>>> monitor dimensions. This should cover the vast majority of use
>>> cases.
>>>
>>> Signed-off-by: Eduard Permyakov <epermyakov at codeweavers.com>
>>> ---
>>>   dlls/winex11.drv/desktop.c | 75 +++++++++++++++++++++++++++++++++++++-
>>>   1 file changed, 73 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/dlls/winex11.drv/desktop.c b/dlls/winex11.drv/desktop.c
>>> index 71b3a0a5a27..37e5624967e 100644
>>> --- a/dlls/winex11.drv/desktop.c
>>> +++ b/dlls/winex11.drv/desktop.c
>>> @@ -20,6 +20,7 @@
>>>    */
>>>     #include "config.h"
>>> +#include <stdint.h>
>>>   #include <X11/cursorfont.h>
>>>   #include <X11/Xlib.h>
>>>   @@ -111,6 +112,74 @@ static void add_desktop_mode( DEVMODEW *mode, DWORD depth, DWORD width, DWORD he
>>>       mode->dmDisplayFrequency = 60;
>>>   }
>>>   +static void get_virtual_edid( unsigned char **edid, unsigned long *len )
>>> +{
>>> +    static const size_t desc_size = 128;
>> You can remove desc_size entirely and use sizeof(default_edid) instead.
>>
>>> +    int i;
>>> +    uint8_t accum = 0;
>>> +    /*Sample EDID for an LCD Desktop IT Display, from VESA spec */
>>> +    static const unsigned char default_edid[128] = {
>>> +        /* Header */
>>> +        0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00,
>>> +        /* Manufacturer's code name */
>>> +        0x04, 0x43,
>>> +        /* Product code */
>>> +        0x06, 0xf2,
>>> +        /* Serial Number */
>>> +        0x01, 0x00, 0x00, 0x00,
>>> +        /* Date of manufacture */
>>> +        0x01, 0x11,
>>> +        /* EDID version */
>>> +        0x01, 0x04,
>>> +        /* Standard characteristics */
>>> +        0x0f, 0x2b, 0x20, 0x78, 0x2b, 0x9c, 0x68, 0xa0,
>>> +        0x57, 0x4a, 0x9b, 0x26, 0x12, 0x48, 0x4c, 0xff,
>>> +        0xff, 0x80, 0xa9, 0x59, 0xa9, 0x4f, 0xa9, 0x4a,
>>> +        0xa9, 0x45, 0x81, 0x99, 0x81, 0x80, 0x61, 0x59,
>>> +        0x45, 0x59,
>>> +        /* First 18-byte data block (Preferred Timing Mode) */
>>> +        0x48, 0x3f, 0x40, 0x30, 0x62, 0xb0, 0x32, 0x40,
>>> +        0x40, 0xc0, 0x13, 0x00, 0xab, 0x40, 0x11, 0x00,
>>> +        0x00, 0x1e,
>>> +        /* Second 18-byte data block */
>>> +        0x00, 0x00, 0x00, 0xfd, 0x00, 0x32, 0x5a, 0x1e,
>>> +        0x6e, 0x17, 0x04, 0x11, 0x00, 0xc8, 0x90, 0x00,
>>> +        0x50, 0x3c,
>>> +        /* Third 18-byte data block */
>>> +        0x00, 0x00, 0x00, 0xf7, 0x00, 0x0a, 0xf7, 0x0f,
>>> +        0x03, 0x87, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00,
>>> +        0x00, 0x00,
>>> +        /* Fourth 18-byte data block */
>>> +        0x00, 0x00, 0x00, 0xfc, 0x00, 0x41, 0x42, 0x43,
>>> +        0x20, 0x4c, 0x43, 0x44, 0x32, 0x31, 0x0a, 0x20,
>>> +        0x20, 0x20,
>>> +        /* Extension flag */
>>> +        0x00,
>>> +    };
>>> +
>>> +    *edid = heap_calloc( desc_size, 1 );
>>> +    if (!*edid)
>>> +    {
>>> +        *len = 0;
>>> +        return;
>>> +    }
>>> +
>>> +    memcpy( *edid, default_edid, sizeof(default_edid) );
>> You can use sizeof(default_edid) - 1 since you don't need to copy the last byte.
>>
>> Anyway, I am not feeling comfortable with the current approach for generating fake EDID data.
>> It's not real enough. For example, physical size should reflect the recommended DPI values and
>> the resolution list should match what's reported from EnumDisplaySettings().
>>
>> In my opinion, you can either generate an EDID by carefully following the VESA EDID standard,
>> or, the other way, which I think it's easier, is to pass the host primary monitor EDID to the
>> virtual desktop by introducing a get_host_primary_monitor_edid(), similar to what get_host_primary_gpu()
>> has done. This way has the benefit of not bothering with the EDID generation and has the
>> same EDID as the host, which can reduce the difference between using virtual desktop and
>> XRandR display device handlers. As for Xinerama, you can leave the EDID empty because
>> Xinerama is rarely used nowadays.
>
> Hi, Zhiyi.
>
> If we are passing the host monitor EDID, then there is little point in using the virtual
> desktop driver, since the app will not respect the constraints of the user-defined virtual
> resolution. As well, there could be some inconsistencies between the data derived from
> the EDID and data queried via APIs which do not rely on the EDID. Also, there can be some
> confusion with regards to which EDID to use when there are multiple physical monitors present.
>
> Generating EDID bit-by-bit from the spec will require quite a bit of tedious code, and it will not
> completely eliminate all instances of bogus data. Things like the resolution list have an associated
> refresh rate associated with the resolution, and it is not obvious what it should be. As well, there
> is a lot of low-level timing data that will simply have to be made up. Since the app that was
> the motivation for making this patch ignores most data in the EDID besides a couple of obvious
> fields, I also have no easy way to test such a change. And I expect that there will pretty much be
> 0 apps targeting Wine that will actually want to parse the EDID and do something meaningful
> with the data.
>
> Personally, I think the use case of using the virtual monitor driver with an app that wants to
> read an EDID is not that important. How about we merge patch 1 and drop patches 2 and 3?

Sure, we can work on it later. I sent a v6 of patch 1 to fix some minor style issue, check NULL before calling XFree()
and fix some possible memory leaks.

Thanks,
Zhiyi


>
>>> +    *len = desc_size;
>>> +
>>> +    /* Set the native resolution in the Preferred Timing Mode descriptor */
>>> +    (*edid)[0x38] = max_width & 0xff;
>>> +    (*edid)[0x3a] = ((max_width >> 8) & 0xf) << 4;
>>> +
>>> +    (*edid)[0x3b] = max_height & 0xff;
>>> +    (*edid)[0x3d] = ((max_height >> 8) & 0xf) << 4;
>>> +
>>> +    /* Set checksum */
>>> +    for (i = 0; i < desc_size-1; i++)
>>> +        accum += (*edid)[i];
>>> +    (*edid)[desc_size - 1] = 256 - accum;
>>> +}
>>> +
>>>   static BOOL X11DRV_desktop_get_modes( ULONG_PTR id, DWORD flags, DEVMODEW **new_modes, UINT *mode_count )
>>>   {
>>>       UINT depth_idx, size_idx, mode_idx = 0;
>>> @@ -265,8 +334,7 @@ static BOOL X11DRV_desktop_get_monitors( ULONG_PTR adapter_id, struct x11drv_mon
>>>       SetRect( &monitor->rc_work, 0, 0, desktop_width, desktop_height );
>>>       query_desktop_work_area( &monitor->rc_work );
>>>       monitor->state_flags = DISPLAY_DEVICE_ATTACHED;
>>> -    monitor->edid_len = 0;
>>> -    monitor->edid = NULL;
>>> +    get_virtual_edid( &monitor->edid, &monitor->edid_len );
>>>       if (desktop_width && desktop_height)
>>>           monitor->state_flags |= DISPLAY_DEVICE_ACTIVE;
>>>   @@ -277,6 +345,9 @@ static BOOL X11DRV_desktop_get_monitors( ULONG_PTR adapter_id, struct x11drv_mon
>>>     static void X11DRV_desktop_free_monitors( struct x11drv_monitor *monitors, int count )
>>>   {
>>> +    int i;
>>> +    for (i = 0; i < count; i++)
>>> +        heap_free( monitors[i].edid );
>>>       heap_free( monitors );
>>>   }
>>>