firmware: microchip: fail auto-update probe if no flash found

There's no point letting the driver probe if there is no flash, as
trying to do a firmware upload will fail. Move the code that attempts
to get the flash from firmware upload to probe, and let it emit a
message to users stating why auto-update is not supported.
The code currently could have a problem if there's a flash in
devicetree, but the system controller driver fails to get a pointer to
it from the mtd subsystem, which will cause
mpfs_sys_controller_get_flash() to return an error. Check for errors and
null, instead of just null, in the new clause.

CC: stable@vger.kernel.org
Fixes: ec5b0f1193ad4 ("firmware: microchip: add PolarFire SoC Auto Update support")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

diff --git a/drivers/firmware/microchip/mpfs-auto-update.c b/drivers/firmware/microchip/mpfs-auto-update.c
index e194f7acb2a9b0f4404a952007c791731ab978cd..8fc3749d4a70989743727b86f3e48d25d34aafaf 100644 (file)
--- a/drivers/firmware/microchip/mpfs-auto-update.c
+++ b/drivers/firmware/microchip/mpfs-auto-update.c
@@ -113,10 +113,6 @@ static enum fw_upload_err mpfs_auto_update_prepare(struct fw_upload *fw_uploader
         * be added here.
         */
 
-       priv->flash = mpfs_sys_controller_get_flash(priv->sys_controller);
-       if (!priv->flash)
-               return FW_UPLOAD_ERR_HW_ERROR;
-
        erase_size = round_up(erase_size, (u64)priv->flash->erasesize);
 
        /*
@@ -427,6 +423,12 @@ static int mpfs_auto_update_probe(struct platform_device *pdev)
                return dev_err_probe(dev, PTR_ERR(priv->sys_controller),
                                     "Could not register as a sub device of the system controller\n");
 
+       priv->flash = mpfs_sys_controller_get_flash(priv->sys_controller);
+       if (IS_ERR_OR_NULL(priv->flash)) {
+               dev_dbg(dev, "No flash connected to the system controller, auto-update not supported\n");
+               return -ENODEV;
+       }
+
        priv->dev = dev;
        platform_set_drvdata(pdev, priv);