On Wed, 10 Apr 2024, Thomas Zimmermann <[email protected]> wrote: > Protect the code in udl_get_edid_block() with drm_dev_enter() and > drm_dev_exit(), so that all callers automatically invoke it. The > function uses hardware resources, which can be hot-unplugged at > any time. The other code in udl_connector_detect() does not use the > resources of the hardware device and therefore does not require > protection. > > This change will allow to use udl_get_edid_block() in various > contexts easily. > > Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Jani Nikula <[email protected]> > --- > drivers/gpu/drm/udl/udl_modeset.c | 20 +++++++++++--------- > 1 file changed, 11 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/udl/udl_modeset.c > b/drivers/gpu/drm/udl/udl_modeset.c > index 751da3a294c44..3df9fc38388b4 100644 > --- a/drivers/gpu/drm/udl/udl_modeset.c > +++ b/drivers/gpu/drm/udl/udl_modeset.c > @@ -434,13 +434,18 @@ static int udl_get_edid_block(void *data, u8 *buf, > unsigned int block, size_t le > struct drm_device *dev = &udl->drm; > struct usb_device *udev = udl_to_usb_device(udl); > u8 *read_buff; > - int ret; > + int idx, ret; > size_t i; > > read_buff = kmalloc(2, GFP_KERNEL); > if (!read_buff) > return -ENOMEM; > > + if (!drm_dev_enter(dev, &idx)) { > + ret = -ENODEV; > + goto err_kfree; > + } > + > for (i = 0; i < len; i++) { > int bval = (i + block * EDID_LENGTH) << 8; > > @@ -449,20 +454,23 @@ static int udl_get_edid_block(void *data, u8 *buf, > unsigned int block, size_t le > 0xA1, read_buff, 2, USB_CTRL_GET_TIMEOUT); > if (ret < 0) { > drm_err(dev, "Read EDID byte %zu failed err %x\n", i, > ret); > - goto err_kfree; > + goto err_drm_dev_exit; > } else if (ret < 1) { > ret = -EIO; > drm_err(dev, "Read EDID byte %zu failed\n", i); > - goto err_kfree; > + goto err_drm_dev_exit; > } > > buf[i] = read_buff[1]; > } > > + drm_dev_exit(idx); > kfree(read_buff); > > return 0; > > +err_drm_dev_exit: > + drm_dev_exit(idx); > err_kfree: > kfree(read_buff); > return ret; > @@ -474,21 +482,15 @@ static enum drm_connector_status > udl_connector_detect(struct drm_connector *conn > struct udl_device *udl = to_udl(dev); > struct udl_connector *udl_connector = to_udl_connector(connector); > enum drm_connector_status status = connector_status_disconnected; > - int idx; > > /* cleanup previous EDID */ > kfree(udl_connector->edid); > udl_connector->edid = NULL; > > - if (!drm_dev_enter(dev, &idx)) > - return connector_status_disconnected; > - > udl_connector->edid = drm_do_get_edid(connector, udl_get_edid_block, > udl); > if (udl_connector->edid) > status = connector_status_connected; > > - drm_dev_exit(idx); > - > return status; > } -- Jani Nikula, Intel
