Messages in this thread Patch in this message | | | From | "Khandelwal, Rajat" <> | Subject | RE: [PATCH] Keep polling IPC status if it reads IPC_STATUS_BUSY or IPC_STATUS_ERR until timeout expires | Date | Wed, 29 Dec 2021 16:13:56 +0000 |
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Hi @Westerberg, Mika This was the original message!
-----Original Message----- From: Khandelwal, Rajat <rajat.khandelwal@intel.com> Sent: Wednesday, December 29, 2021 7:00 PM To: mika.westerberg@linux.intel.com Cc: Khandelwal, Rajat <rajat.khandelwal@intel.com>; linux-kernel@vger.kernel.org; platform-driver-x86@vger.kernel.org Subject: [PATCH] Keep polling IPC status if it reads IPC_STATUS_BUSY or IPC_STATUS_ERR until timeout expires
The current implementation returns -EIO if and when IPC_STATUS_ERR is returned and returns -ETIMEDOUT even if the status is busy. This patch polls the IPC status even if IPC_STATUS_ERR is returned until timeout expires and returns -EBUSY if the status shows busy. Observed in multiple scenarios, trying to fetch the status of IPC after it shows ERR sometimes eradicates the ERR status.
Signed-off-by: Rajat-Khandelwal <rajat.khandelwal@intel.com> --- drivers/platform/x86/intel_scu_ipc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c index 7cc9089d1e14..91f716e84474 100644 --- a/drivers/platform/x86/intel_scu_ipc.c +++ b/drivers/platform/x86/intel_scu_ipc.c @@ -233,17 +233,19 @@ static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset) static inline int busy_loop(struct intel_scu_ipc_dev *scu) { unsigned long end = jiffies + IPC_TIMEOUT; + u32 status; do { - u32 status; - status = ipc_read_status(scu); if (!(status & IPC_STATUS_BUSY)) { - return (status & IPC_STATUS_ERR) ? -EIO : 0; + if (!(status & IPC_STATUS_ERR)) + return 0; + } usleep_range(50, 100); } while (time_before(jiffies, end)); + if (status & IPC_STATUS_BUSY) + return -EBUSY; + if (status & IPC_STATUS_ERR) + return -EIO; + return -ETIMEDOUT; } -- 2.17.1
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