Commit 29237e6d authored by Sudeep Holla's avatar Sudeep Holla Committed by Jassi Brar
Browse files

mailbox: pcc: Drop unnecessary endianness conversion of pcc_hdr.flags 



The Sparse static checker flags a type mismatch warning related to
endianness conversion:

  |  warning: incorrect type in argument 1 (different base types)
  |     expected restricted __le32 const [usertype] *p
  |     got unsigned int *

This is because an explicit endianness conversion (le32_to_cpu()) was
applied unnecessarily to a pcc_hdr.flags field that is already in
little-endian format.

The PCC driver is only enabled on little-endian kernels due to its
dependency on ACPI and EFI, making the explicit conversion unnecessary.

The redundant conversion occurs in pcc_chan_check_and_ack() for the
pcc_hdr.flags field. Drop this unnecessary endianness conversion of
pcc_hdr.flags.

Also drop the redundant PCC_ACK_FLAG_MASK definition and use the
more appropriate and already defined PCC_CMD_COMPLETION_NOTIFY.

Acked-by: default avatarHuisong Li <lihuisong@huawei.com>
Tested-by: default avatarAdam Young <admiyo@os.amperecomputing.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: default avatarJassi Brar <jassisinghbrar@gmail.com>
parent cf1338c0

drivers/mailbox/pcc.c

+1 −1
Original line number Diff line number Diff line
@@ -292,7 +292,7 @@ static void check_and_ack(struct pcc_chan_info *pchan, struct mbox_chan *chan) 
	 *

	 * The PCC master subspace channel clears chan_in_use to free channel.

	 */

	if (le32_to_cpup(&pcc_hdr.flags) & PCC_ACK_FLAG_MASK)

	if (pcc_hdr.flags & PCC_CMD_COMPLETION_NOTIFY)

		pcc_send_data(chan, NULL);

	else

		pcc_chan_reg_read_modify_write(&pchan->cmd_update);

include/acpi/pcc.h

+0 −1
Original line number Diff line number Diff line
@@ -32,7 +32,6 @@ struct pcc_mbox_chan { 
#define PCC_CMD_COMPLETION_NOTIFY	BIT(0)



#define MAX_PCC_SUBSPACES	256

#define PCC_ACK_FLAG_MASK	0x1



#ifdef CONFIG_PCC

extern struct pcc_mbox_chan *