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Initialize and map the PCC shared memory (SHMEM) prior to > calling mbox_bind_client() so that clients never observe an uninitialized > or NULL SHMEM during bind-time callbacks or early use in startup(). > > This makes the PCC mailbox channel bring-up order consistent and > eliminates a race between SHMEM setup and client binding. > > This will be needed in channel startup to clear/acknowledge any pending > interrupts before enabling them. > > Signed-off-by: Sudeep Holla > --- > drivers/mailbox/pcc.c | 18 ++++++++++-------- > 1 file changed, 10 insertions(+), 8 deletions(-) > > diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c > index 33bd2d05704b..2829ec51b47f 100644 > --- a/drivers/mailbox/pcc.c > +++ b/drivers/mailbox/pcc.c > @@ -378,18 +378,20 @@ pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id) > return ERR_PTR(-EBUSY); > } > > - rc = mbox_bind_client(chan, cl); > - if (rc) > - return ERR_PTR(rc); > - > pcc_mchan = &pchan->chan; > pcc_mchan->shmem = acpi_os_ioremap(pcc_mchan->shmem_base_addr, > pcc_mchan->shmem_size); > - if (pcc_mchan->shmem) > - return pcc_mchan; > + if (!pcc_mchan->shmem) > + return ERR_PTR(-ENXIO); > > - mbox_free_channel(chan); > - return ERR_PTR(-ENXIO); > + rc = mbox_bind_client(chan, cl); > + if (rc) { > + iounmap(pcc_mchan->shmem); > + pcc_mchan->shmem = NULL; > + return ERR_PTR(rc); > + } > + > + return pcc_mchan; > } > EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); > >