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From 3394fabbd17ad7263feeb0f4ae593056237f0647 Mon Sep 17 00:00:00 2001
From: Jae Hyun Yoo <jae.hyun.yoo@intel.com>
Date: Tue, 30 Jul 2019 13:01:58 -0700
Subject: [PATCH] peci: add a temporary workaround
To cover a PECI issue, this commit makes PECI driver block all PECI
commands when PLTRST_N signal is 0.
Also, it adds 'use_wa' module parameter for platforms that don't have
the PLTRST_N gpio input so that the WA can be disabled through the
module parameter.
This is a temporary workaround.
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@intel.com>
---
drivers/peci/busses/peci-aspeed.c | 11 +++++++++++
drivers/peci/peci-core.c | 11 +++++++++++
include/linux/peci.h | 1 +
3 files changed, 23 insertions(+)
diff --git a/drivers/peci/busses/peci-aspeed.c b/drivers/peci/busses/peci-aspeed.c
index 8a0dd40730cc..76394ab32854 100644
--- a/drivers/peci/busses/peci-aspeed.c
+++ b/drivers/peci/busses/peci-aspeed.c
@@ -10,6 +10,7 @@
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_gpio.h>
#include <linux/peci.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
@@ -445,6 +446,16 @@ static int aspeed_peci_probe(struct platform_device *pdev)
if (ret)
goto err_put_adapter_dev;
+ priv->adapter->pltrst_pin = of_get_gpio(pdev->dev.of_node, 0);
+ if (gpio_is_valid(priv->adapter->pltrst_pin)) {
+ ret = devm_gpio_request(&pdev->dev, priv->adapter->pltrst_pin,
+ "peci-aspeed");
+ if (ret < 0) {
+ priv->adapter->pltrst_pin = -1;
+ dev_err(&pdev->dev, "error requesting pltrst gpio\n");
+ }
+ }
+
ret = peci_add_adapter(priv->adapter);
if (ret)
goto err_put_adapter_dev;
diff --git a/drivers/peci/peci-core.c b/drivers/peci/peci-core.c
index b99ba788a032..2e3b9a0c83e9 100644
--- a/drivers/peci/peci-core.c
+++ b/drivers/peci/peci-core.c
@@ -5,6 +5,7 @@
#include <linux/crc8.h>
#include <linux/delay.h>
#include <linux/mm.h>
+#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/peci.h>
@@ -190,6 +191,11 @@ static int peci_aw_fcs(struct peci_xfer_msg *msg, int len, u8 *aw_fcs)
return 0;
}
+/* Temporary WA */
+static bool use_wa __read_mostly = true;
+module_param_named(use_wa, use_wa, bool, 0644);
+MODULE_PARM_DESC(use_wa, "flag for enabling of WA");
+
static int __peci_xfer(struct peci_adapter *adapter, struct peci_xfer_msg *msg,
bool do_retry, bool has_aw_fcs)
{
@@ -197,6 +203,11 @@ static int __peci_xfer(struct peci_adapter *adapter, struct peci_xfer_msg *msg,
u8 aw_fcs;
int ret;
+ /* Temporary WA */
+ if (use_wa && gpio_is_valid(adapter->pltrst_pin) &&
+ gpio_get_value(adapter->pltrst_pin) == 0)
+ return -EAGAIN;
+
/*
* In case if adapter uses DMA, check at here whether tx and rx buffers
* are DMA capable or not.
diff --git a/include/linux/peci.h b/include/linux/peci.h
index 6fc424dc2a73..e589cb258a2a 100644
--- a/include/linux/peci.h
+++ b/include/linux/peci.h
@@ -44,6 +44,7 @@ struct peci_adapter {
struct peci_xfer_msg *msg);
u32 cmd_mask;
bool use_dma;
+ int pltrst_pin;
};
static inline struct peci_adapter *to_peci_adapter(void *d)
--
2.7.4
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