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Message-ID: <149a44d0456b2f0b48be13ba51aeaccc33651073.camel@apache.org>
Subject: Re: [PATCH v5] Fix modifier keys for Redragon Asura Keyboard
From:   Robert Munteanu <rombert@apache.org>
To:     Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc:     Jiri Kosina <jikos@kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        "open list:HID CORE LAYER" <linux-input@vger.kernel.org>
Date:   Mon, 16 Apr 2018 13:14:18 +0300
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References: <20180411094953.12053-1-rombert@apache.org>
         <CAO-hwJKbYyZdtq=zg_ZeJOiL=5cTbD4oKuWmpF-P_7TgBkqVYA@mail.gmail.com>
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Hi Benjamin and Jiri,

On Mon, 2018-04-16 at 12:02 +0200, Benjamin Tissoires wrote:
> Hi Robert,
> 
> On Wed, Apr 11, 2018 at 11:49 AM, Robert Munteanu <rombert@apache.org
> > wrote:
> > Changelog:
> > 
> > - v2: modifier keys work, some combinations are still troublesome
> > - v3: style cleanup, rebase on top of 4.14
> > - v4: remove most debugging calls, make init info useful for user,
> >   rebased on top of 4.15
> > - v5: fix the HID descriptor as suggested by Benjamin Tissoires,
> >   use existing USB vendor id, update comment style, add SPDX
> >   license identifier, rename to hid-redragon, stop registering
> >   two input devices, rebased on top of 4.16
> 
> As Jiri said, please provide a correct commit message.

Will do.

> 
> I have a few nitpicks in the driver, v6 should be fine:
> 
> > 
> > Signed-off-by: Robert Munteanu <rombert@apache.org>
> > ---
> >  drivers/hid/Kconfig        |  7 ++++
> >  drivers/hid/Makefile       |  1 +
> >  drivers/hid/hid-ids.h      |  1 +
> >  drivers/hid/hid-quirks.c   |  3 ++
> >  drivers/hid/hid-redragon.c | 89
> > ++++++++++++++++++++++++++++++++++++++++++++++
> >  5 files changed, 101 insertions(+)
> >  create mode 100644 drivers/hid/hid-redragon.c
> > 
> > diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> > index 19c499f5623d..1125e4813716 100644
> > --- a/drivers/hid/Kconfig
> > +++ b/drivers/hid/Kconfig
> > @@ -560,6 +560,13 @@ config HID_MAYFLASH
> >         Say Y here if you have HJZ Mayflash PS3 game controller
> > adapters
> >         and want to enable force feedback support.
> > 
> > +config HID_REDRAGON
> > +       tristate "Redragon keyboards"
> > +       depends on HID
> > +       default !EXPERT
> > +       ---help---
> > +    Support for Redragon keyboards that need fix-ups to work
> > properly.
> > +
> >  config HID_MICROSOFT
> >         tristate "Microsoft non-fully HID-compliant devices"
> >         depends on HID
> > diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> > index eb13b9e92d85..a36f3f40ba63 100644
> > --- a/drivers/hid/Makefile
> > +++ b/drivers/hid/Makefile
> > @@ -84,6 +84,7 @@ hid-picolcd-$(CONFIG_DEBUG_FS)                +=
> > hid-picolcd_debugfs.o
> > 
> >  obj-$(CONFIG_HID_PLANTRONICS)  += hid-plantronics.o
> >  obj-$(CONFIG_HID_PRIMAX)       += hid-primax.o
> > +obj-$(CONFIG_HID_REDRAGON)     += hid-redragon.o
> >  obj-$(CONFIG_HID_RETRODE)      += hid-retrode.o
> >  obj-$(CONFIG_HID_ROCCAT)       += hid-roccat.o hid-roccat-common.o 
> > \
> >         hid-roccat-arvo.o hid-roccat-isku.o hid-roccat-kone.o \
> > diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> > index 9454ac134ce2..41a64d0e91f9 100644
> > --- a/drivers/hid/hid-ids.h
> > +++ b/drivers/hid/hid-ids.h
> > @@ -599,6 +599,7 @@
> >  #define USB_VENDOR_ID_JESS             0x0c45
> >  #define USB_DEVICE_ID_JESS_YUREX       0x1010
> >  #define USB_DEVICE_ID_ASUS_MD_5112     0x5112
> > +#define USB_DEVICE_ID_REDRAGON_ASURA   0x760b
> > 
> >  #define USB_VENDOR_ID_JESS2            0x0f30
> >  #define USB_DEVICE_ID_JESS2_COLOR_RUMBLE_PAD 0x0111
> > diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
> > index e92b77fa574a..5f1253f1739a 100644
> > --- a/drivers/hid/hid-quirks.c
> > +++ b/drivers/hid/hid-quirks.c
> > @@ -557,6 +557,9 @@ static const struct hid_device_id
> > hid_have_special_driver[] = {
> >  #if IS_ENABLED(CONFIG_HID_PRODIKEYS)
> >         { HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS,
> > USB_DEVICE_ID_PRODIKEYS_PCMIDI) },
> >  #endif
> > +#if IS_ENABLED(CONFIG_HID_REDRAGON)
> > +       {
> > HID_USB_DEVICE(USB_VENDOR_ID_JESS,  USB_DEVICE_ID_REDRAGON_ASURA)
> > },
> > +#endif
> 
> Please drop this hunk. v4.16 should work without changing
> hid_have_special_driver. This way, you will be sure that an initramfs
> that doesn't include hid-redragon.ko will allo people to type their
> LUKS password.

I recall testing without this change resulted in the driver not being
picked up. I will retest ( running 4.16.0 here, can update to 4.16.1
soon ). In case the driver is not picked up, where should I start
looking?

> 
> >  #if IS_ENABLED(CONFIG_HID_RETRODE)
> >         { HID_USB_DEVICE(USB_VENDOR_ID_FUTURE_TECHNOLOGY,
> > USB_DEVICE_ID_RETRODE2) },
> >  #endif
> > diff --git a/drivers/hid/hid-redragon.c b/drivers/hid/hid-
> > redragon.c
> > new file mode 100644
> > index 000000000000..ff98a5dbb8e2
> > --- /dev/null
> > +++ b/drivers/hid/hid-redragon.c
> > @@ -0,0 +1,89 @@
> > +/*
> > + *  HID driver for Redragon keyboards
> > + *
> > + *  Copyright (c) 2017 Robert Munteanu
> > + *  SPDX-License-Identifier: GPL-2.0
> > + */
> > +
> > +/*
> > + * This program is free software; you can redistribute it and/or
> > modify it
> > + * under the terms of the GNU General Public License as published
> > by the Free
> > + * Software Foundation; either version 2 of the License, or (at
> > your option)
> > + * any later version.
> > + */
> > +
> > +#include <linux/device.h>
> > +#include <linux/input.h>
> 
> you probably don't need input.h
> 
> > +#include <linux/hid.h>
> > +#include <linux/module.h>
> > +#include <linux/log2.h>
> 
> log2.h? I am not sure you need it either
> 
> > +#include <linux/input-event-codes.h>
> 
> probably drop this one too.

I'll drop the missing imports, those are leftovers from my initial
work.

> 
> > +
> > +#include "hid-ids.h"
> > +
> > +
> > +/*
> > + * The Redragon Asura keyboard sends an incorrect HID descriptor.
> > + * At byte 100 it contains
> > + *
> > + *   0x81, 0x00
> > + *
> > + * which is Input (Data, Arr, Abs), but it should be
> > + *
> > + *   0x81, 0x02
> > + *
> > + * which is Input (Data, Var, Abs), which is consistent with the
> > way
> > + * key codes are generated.
> > + */
> > +
> > +static __u8 *redragon_report_fixup(struct hid_device *hdev, __u8
> > *rdesc,
> > +       unsigned int *rsize)
> > +{
> > +       if (*rsize >= 102 && rdesc[100] == 0x81 && rdesc[101] ==
> > 0x00) {
> > +               dev_info(&hdev->dev, "Fixing Redragon ASURA report
> > descriptor.\n");
> > +               rdesc[101] = 0x02;
> > +       }
> > +
> > +       return rdesc;
> > +}
> > +
> > +static int redragon_probe(struct hid_device *dev,
> > +       const struct hid_device_id *id)
> > +{
> > +       int ret;
> > +
> > +       ret = hid_parse(dev);
> > +       if (ret) {
> > +               hid_err(dev, "parse failed\n");
> > +               return ret;
> > +       }
> > +
> > +       /* do not register unused input device */
> > +       if (dev->maxapplication == 1)
> > +               return 0;
> > +
> > +       ret = hid_hw_start(dev, HID_CONNECT_DEFAULT);
> > +       if (ret) {
> > +               hid_err(dev, "hw start failed\n");
> > +               return ret;
> > +       }
> > +
> > +       return 0;
> > +}
> > +static const struct hid_device_id redragon_devices[] = {
> > +       {HID_USB_DEVICE(USB_VENDOR_ID_JESS,
> > USB_DEVICE_ID_REDRAGON_ASURA)},
> > +       {}
> > +};
> > +
> > +MODULE_DEVICE_TABLE(hid, redragon_devices);
> > +
> > +static struct hid_driver redragon_driver = {
> > +       .name = "redragon",
> > +       .id_table = redragon_devices,
> > +       .report_fixup = redragon_report_fixup,
> > +       .probe = redragon_probe
> > +};
> > +
> > +module_hid_driver(redragon_driver);
> > +
> > +MODULE_LICENSE("GPL");
> 
> The SPDX header says GPL-v2. And IIRC if there is the SPDX header you
> can drop the MODULE_LICENSE (not entirely sure though).

Ack, will adjust and re-test.

Thanks for the review,

Robert