From 38c695e1e2a2caaacb3b2dc5cddbba5e8024412f Mon Sep 17 00:00:00 2001 From: Tanveer Alam Date: Mon, 28 Mar 2022 16:21:37 +0530 Subject: [PATCH] usb: typec: mux: intel_pmc_mux: Add retry logic to a PMC command There are few scenerio when PMC reports 'busy condition' and command fail. If PMC receives a high priority command while servicing a low priority command then it discards the low priority command and start servicing the high priority command. The lower priority command fail and driver returns error. If the same command resend to the PMC then PMC latches the command and service it accordingly. Thus adds the retry logic for the PMC command. Reviewed-by: Heikki Krogerus Signed-off-by: Tanveer Alam Link: https://lore.kernel.org/r/20220328105137.6223-1-tanveer1.alam@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/mux/intel_pmc_mux.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c index 2cdd221..da6b381 100644 --- a/drivers/usb/typec/mux/intel_pmc_mux.c +++ b/drivers/usb/typec/mux/intel_pmc_mux.c @@ -173,7 +173,7 @@ static int hsl_orientation(struct pmc_usb_port *port) return port->orientation - 1; } -static int pmc_usb_command(struct pmc_usb_port *port, u8 *msg, u32 len) +static int pmc_usb_send_command(struct intel_scu_ipc_dev *ipc, u8 *msg, u32 len) { u8 response[4]; u8 status_res; @@ -184,7 +184,7 @@ static int pmc_usb_command(struct pmc_usb_port *port, u8 *msg, u32 len) * Status can be checked from the response message if the * function intel_scu_ipc_dev_command succeeds. */ - ret = intel_scu_ipc_dev_command(port->pmc->ipc, PMC_USBC_CMD, 0, msg, + ret = intel_scu_ipc_dev_command(ipc, PMC_USBC_CMD, 0, msg, len, response, sizeof(response)); if (ret) @@ -203,6 +203,23 @@ static int pmc_usb_command(struct pmc_usb_port *port, u8 *msg, u32 len) return 0; } +static int pmc_usb_command(struct pmc_usb_port *port, u8 *msg, u32 len) +{ + int retry_count = 3; + int ret; + + /* + * If PMC is busy then retry the command once again + */ + while (retry_count--) { + ret = pmc_usb_send_command(port->pmc->ipc, msg, len); + if (ret != -EBUSY) + break; + } + + return ret; +} + static int pmc_usb_mux_dp_hpd(struct pmc_usb_port *port, struct typec_displayport_data *dp) { -- 2.7.4