Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Amelie Delaunay <amelie.delaunay@foss.st.com>
To:     Minas Harutyunyan <hminas@synopsys.com>,
        Felipe Balbi <balbi@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        Fabrice Gasnier <fabrice.gasnier@foss.st.com>,
        Amelie Delaunay <amelie.delaunay@foss.st.com>
Subject: [PATCH v2 1/3] usb: dwc2: set ahbcfg parameter for STM32MP15 OTG HS and FS
Date:   Tue, 5 Jan 2021 10:48:53 +0100
Message-ID: <20210105094855.30763-2-amelie.delaunay@foss.st.com>
In-Reply-To: <20210105094855.30763-1-amelie.delaunay@foss.st.com>
References: <20210105094855.30763-1-amelie.delaunay@foss.st.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

STM32MP15 ahbcfg register default value sets Burst length/type (HBSTLEN)
to Single (32-bit accesses on AHB), which is not recommended, according
to STM32MP157 Reference manual [1].
This patch sets Burst length/type (HBSTLEN) so that bus transactions
target 16x32 bit accesses. This improves OTG controller performance.

[1] https://www.st.com/resource/en/reference_manual/dm00327659.pdf, p.3149

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
---
 drivers/usb/dwc2/params.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
index 267543c3dc38..0df693319f0a 100644
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -177,6 +177,7 @@ static void dwc2_set_stm32mp15_fsotg_params(struct dwc2_hsotg *hsotg)
 	p->i2c_enable = false;
 	p->activate_stm_fs_transceiver = true;
 	p->activate_stm_id_vb_detection = true;
+	p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 << GAHBCFG_HBSTLEN_SHIFT;
 	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;
 }
 
@@ -189,6 +190,7 @@ static void dwc2_set_stm32mp15_hsotg_params(struct dwc2_hsotg *hsotg)
 	p->host_rx_fifo_size = 440;
 	p->host_nperio_tx_fifo_size = 256;
 	p->host_perio_tx_fifo_size = 256;
+	p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 << GAHBCFG_HBSTLEN_SHIFT;
 	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;
 }
 
-- 
2.17.1