[PATCH 2/4] qxl: limit monitor config read retries

Gerd Hoffmann
2017-03-08T09:19:04Z

When reading the monitor config fails, don't retry forever. If it fails
ten times in a row just give up to avoid the driver hangs. Also add a
small delay after each attempt, so the host has a chance to complete a
partial update.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
drivers/gpu/drm/qxl/qxl_display.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c
index 2cd14be..2b99496 100644
--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@@ -157,19 +157,23 @@ static void qxl_update_offset_props(struct qxl_device *qdev)

void qxl_display_read_client_monitors_config(struct qxl_device *qdev)
{
-
struct drm_device *dev = &qdev->ddev;
- int status;
+ int status, retries;

- status = qxl_display_copy_rom_client_monitors_config(qdev);
- while (status == MONITORS_CONFIG_BAD_CRC) {
- qxl_io_log(qdev, "failed crc check for client_monitors_config,"
- " retrying\n");
+ for (retries = 0; retries < 10; retries++) {
status = qxl_display_copy_rom_client_monitors_config(qdev);
+ if (status != MONITORS_CONFIG_BAD_CRC)
+ break;
+ udelay(5);
+ }
+ if (status == MONITORS_CONFIG_BAD_CRC) {
+ qxl_io_log(qdev, "config: bad crc\n");
+ DRM_DEBUG_KMS("ignoring client monitors config: bad crc");
+ return;
}
if (status == MONITORS_CONFIG_UNCHANGED) {
- qxl_io_log(qdev, "config unchanged\n");
- DRM_DEBUG("ignoring unchanged client monitors config");
+ qxl_io_log(qdev, "config: unchanged\n");
+ DRM_DEBUG_KMS("ignoring client monitors config: unchanged");
return;
}

--
1.8.3.1

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