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authorRussell Currey <ruscur@russell.cc>2016-04-07 16:28:26 +1000
committerWilly Tarreau <w@1wt.eu>2016-08-21 23:22:45 +0200
commit628cb1780bca2d899d76b29fd6884fa73d243c7c (patch)
tree9ec540ae2fc9f43c5cf8d42e971b4fedc162d1b7
parent0d330892ab7d7e1c0f1969250659deb11fe967b7 (diff)
downloadlinux-stable-rt-628cb1780bca2d899d76b29fd6884fa73d243c7c.tar.gz
powerpc/pseries/eeh: Handle RTAS delay requests in configure_bridge
commit 871e178e0f2c4fa788f694721a10b4758d494ce1 upstream. In the "ibm,configure-pe" and "ibm,configure-bridge" RTAS calls, the spec states that values of 9900-9905 can be returned, indicating that software should delay for 10^x (where x is the last digit, i.e. 990x) milliseconds and attempt the call again. Currently, the kernel doesn't know about this, and respecting it fixes some PCI failures when the hypervisor is busy. The delay is capped at 0.2 seconds. Cc: <stable@vger.kernel.org> # 3.10+ Signed-off-by: Russell Currey <ruscur@russell.cc> Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
-rw-r--r--arch/powerpc/platforms/pseries/eeh_pseries.c51
1 files changed, 36 insertions, 15 deletions
diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 68f97d5a467968..dc0278e7fd9103 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c
@@ -551,29 +551,50 @@ static int pseries_eeh_configure_bridge(struct eeh_pe *pe)
{
int config_addr;
int ret;
+ /* Waiting 0.2s maximum before skipping configuration */
+ int max_wait = 200;
/* Figure out the PE address */
config_addr = pe->config_addr;
if (pe->addr)
config_addr = pe->addr;
- /* Use new configure-pe function, if supported */
- if (ibm_configure_pe != RTAS_UNKNOWN_SERVICE) {
- ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
- config_addr, BUID_HI(pe->phb->buid),
- BUID_LO(pe->phb->buid));
- } else if (ibm_configure_bridge != RTAS_UNKNOWN_SERVICE) {
- ret = rtas_call(ibm_configure_bridge, 3, 1, NULL,
- config_addr, BUID_HI(pe->phb->buid),
- BUID_LO(pe->phb->buid));
- } else {
- return -EFAULT;
- }
+ while (max_wait > 0) {
+ /* Use new configure-pe function, if supported */
+ if (ibm_configure_pe != RTAS_UNKNOWN_SERVICE) {
+ ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
+ config_addr, BUID_HI(pe->phb->buid),
+ BUID_LO(pe->phb->buid));
+ } else if (ibm_configure_bridge != RTAS_UNKNOWN_SERVICE) {
+ ret = rtas_call(ibm_configure_bridge, 3, 1, NULL,
+ config_addr, BUID_HI(pe->phb->buid),
+ BUID_LO(pe->phb->buid));
+ } else {
+ return -EFAULT;
+ }
- if (ret)
- pr_warning("%s: Unable to configure bridge PHB#%d-PE#%x (%d)\n",
- __func__, pe->phb->global_number, pe->addr, ret);
+ if (!ret)
+ return ret;
+
+ /*
+ * If RTAS returns a delay value that's above 100ms, cut it
+ * down to 100ms in case firmware made a mistake. For more
+ * on how these delay values work see rtas_busy_delay_time
+ */
+ if (ret > RTAS_EXTENDED_DELAY_MIN+2 &&
+ ret <= RTAS_EXTENDED_DELAY_MAX)
+ ret = RTAS_EXTENDED_DELAY_MIN+2;
+
+ max_wait -= rtas_busy_delay_time(ret);
+
+ if (max_wait < 0)
+ break;
+
+ rtas_busy_delay(ret);
+ }
+ pr_warn("%s: Unable to configure bridge PHB#%d-PE#%x (%d)\n",
+ __func__, pe->phb->global_number, pe->addr, ret);
return ret;
}