The patch below does not apply to the 3.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 871e178e0f2c4fa788f694721a10b4758d494ce1 Mon Sep 17 00:00:00 2001
From: Russell Currey <ruscur@xxxxxxxxxx>
Date: Thu, 7 Apr 2016 16:28:26 +1000
Subject: [PATCH] powerpc/pseries/eeh: Handle RTAS delay requests in
configure_bridge
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@xxxxxxxxxxxxxxx> # 3.10+
Signed-off-by: Russell Currey <ruscur@xxxxxxxxxx>
Acked-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index ac3ffd97e059..405baaf96864 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c
@@ -615,29 +615,50 @@ 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_warn("%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;
}
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