[PATCH] drm/qxl: replace idr_init() by idr_init_base()

[PATCH] drm/qxl: replace idr_init() by idr_init_base()

[Deepak R Varma]

idr_init() uses base 0 which is an invalid identifier for this driver.
The idr_alloc for this driver uses 1 as start value for ID range. The
new function idr_init_base allows IDR to set the ID lookup from base 1.
This avoids all lookups that otherwise starts from 0 since 0 is always
unused / available.

References: commit 6ce711f27500 ("idr: Make 1-based IDRs more efficient")

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
---
 drivers/gpu/drm/qxl/qxl_kms.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/qxl/qxl_kms.c b/drivers/gpu/drm/qxl/qxl_kms.c
index dc5b3850a4d4..228e2b9198f1 100644
--- a/drivers/gpu/drm/qxl/qxl_kms.c
+++ b/drivers/gpu/drm/qxl/qxl_kms.c
@@ -231,11 +231,11 @@ int qxl_device_init(struct qxl_device *qdev,
 		goto cursor_ring_free;
 	}
 
-	idr_init(&qdev->release_idr);
+	idr_init_base(&qdev->release_idr, 1);
 	spin_lock_init(&qdev->release_idr_lock);
 	spin_lock_init(&qdev->release_lock);
 
-	idr_init(&qdev->surf_id_idr);
+	idr_init_base(&qdev->surf_id_idr, 1);
 	spin_lock_init(&qdev->surf_id_idr_lock);
 
 	mutex_init(&qdev->async_io_mutex);
-- 
2.25.1

Re: [PATCH] drm/qxl: replace idr_init() by idr_init_base()

[Gerd Hoffmann]

On Fri, Nov 06, 2020 at 12:20:16AM +0530, Deepak R Varma wrote:
> idr_init() uses base 0 which is an invalid identifier for this driver.
> The idr_alloc for this driver uses 1 as start value for ID range. The
> new function idr_init_base allows IDR to set the ID lookup from base 1.
> This avoids all lookups that otherwise starts from 0 since 0 is always
> unused / available.
> 
> References: commit 6ce711f27500 ("idr: Make 1-based IDRs more efficient")
> 
> Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>

Pushed to drm-misc-next.

thanks,
  Gerd