Commit 713e468c authored by Ritesh Harjani (IBM)'s avatar Ritesh Harjani (IBM) Committed by Madhavan Srinivasan
Browse files

pseries/papr-hvpipe: Fix & simplify error handling in papr_hvpipe_init() 



Remove such 3 levels of nesting patterns to check success return values
from function calls.

ret = enable_hvpipe_IRQ()
    if (!ret)
	    ret = set_hvpipe_sys_param(1)
	        if (!ret)
		    ret = misc_register()

Instead just bail out to "out*:" labels, in case of any error. This
simplifies the init flow.

While at it let's also fix the following error handling logic:
We have already enabled interrupt sources and enabled hvpipe to received
interrupts, if misc_register() fails, we will destroy the workqueue, but
the HMC might send us a msg via hvpipe which will call, queue work on
the workqueue which might be destroyed.

So instead, let's reverse the order of enabling set_hvpipe_sys_param(1)
and in case of an error let's remove the misc dev by calling
misc_deregister().

Cc: stable@vger.kernel.org
Fixes: 39a08a4f ("powerpc/pseries: Enable hvpipe with ibm,set-system-parameter RTAS")
Signed-off-by: default avatarRitesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: default avatarMadhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/f2141eafb80e7780395e03aa9a22e8a37be80513.1777606826.git.ritesh.list@gmail.com
parent 1b9f7aaf

arch/powerpc/platforms/pseries/papr-hvpipe.c

+17 −11
Original line number Diff line number Diff line
@@ -780,23 +780,29 @@ static int __init papr_hvpipe_init(void) 
	}



	ret = enable_hvpipe_IRQ();

	if (!ret) {

		ret = set_hvpipe_sys_param(1);

		if (!ret)

	if (ret)

		goto out_wq;



	ret = misc_register(&papr_hvpipe_dev);

	}

	if (ret)

		goto out_wq;



	ret = set_hvpipe_sys_param(1);

	if (ret)

		goto out_misc;



	if (!ret) {

	pr_info("hvpipe feature is enabled\n");

	hvpipe_feature = true;

	return 0;

	}



	pr_err("hvpipe feature is not enabled %d\n", ret);

out_misc:

	misc_deregister(&papr_hvpipe_dev);

out_wq:

	destroy_workqueue(papr_hvpipe_wq);

out:

	kfree(papr_hvpipe_work);

	papr_hvpipe_work = NULL;

	pr_err("hvpipe feature is not enabled %d\n", ret);

	return ret;

}

machine_device_initcall(pseries, papr_hvpipe_init);