Re: [PATCH v8 2/4] firmware: raspberrypi: Introduce vl805 init routine

From: Stefan Wahren <wahrenst@gmx.net>
To: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: Rob Herring <robh@kernel.org>,
	f.fainelli@gmail.com, gregkh@linuxfoundation.org,
	helgaas@kernel.org, linux-kernel@vger.kernel.org,
	Ray Jui <rjui@broadcom.com>,
	Scott Branden <sbranden@broadcom.com>,
	bcm-kernel-feedback-list@broadcom.com, linux-pci@vger.kernel.org,
	tim.gover@raspberrypi.org, linux-usb@vger.kernel.org,
	linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v8 2/4] firmware: raspberrypi: Introduce vl805 init routine
Date: Sat, 9 May 2020 12:02:55 +0200	[thread overview]
Message-ID: <c9449111-f646-3925-36e6-f4492ad5f90a@gmx.net> (raw)
In-Reply-To: <20200507214859.GA562@bogus>

Hi Nicolas,

Am 07.05.20 um 23:48 schrieb Rob Herring:
> On Tue,  5 May 2020 18:13:15 +0200, Nicolas Saenz Julienne wrote:
>> The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip
>> that implements xHCI. After a PCI reset, VL805's firmware may either be
>> loaded directly from an EEPROM or, if not present, by the SoC's
>> co-processor, VideoCore. RPi4's VideoCore OS contains both the non public
>> firmware load logic and the VL805 firmware blob. The function this patch
>> introduces triggers the aforementioned process.
>>
>> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>>
>> ---
>>
>> Change since v7:
>> - Use usleep_delay()
>> - Add comment about PCI errors
>> - Don't wait on error
>> - Typos
>>
>> Change since v6:
>> - Add test to avoid loading the firmware when not needed
>> - Since we have it around, print VL805's firmware version, it'll make
>> debugging easier in the future
>> - Correct typos
>> - Add a clearer view of HW topology in patch description
>>
>> Changes since v4:
>> - Inline function definition when RASPBERRYPI_FIRMWARE is not defined
>>
>> Changes since v1:
>> - Move include into .c file and add forward declaration to .h
>>
>>  drivers/firmware/raspberrypi.c             | 61 ++++++++++++++++++++++
>>  include/soc/bcm2835/raspberrypi-firmware.h |  7 +++
>>  2 files changed, 68 insertions(+)
>>
> Reviewed-by: Rob Herring <robh@kernel.org>

i modified the code a little bit for testing, but also successfully
tested it without my modifications:

diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
index 0d1422b..f3f4c2d 100644
--- a/drivers/firmware/raspberrypi.c
+++ b/drivers/firmware/raspberrypi.c
@@ -337,8 +337,10 @@ int rpi_firmware_init_vl805(struct pci_dev *pdev)
         * further down the line.
         */
        pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET,
&version);
-       if (version)
-               goto exit;
+       if (version) {
+               pci_info(pdev, "VL805 EEPROM firmware version %08x\n",
version);
+               return 0;
+       }
 
        dev_addr = pdev->bus->number << 20 | PCI_SLOT(pdev->devfn) << 15 |
                   PCI_FUNC(pdev->devfn) << 12;
@@ -353,9 +355,8 @@ int rpi_firmware_init_vl805(struct pci_dev *pdev)
 
        pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET,
                              &version);
-exit:
-       pci_info(pdev, "VL805 firmware version %08x\n", version);
 
+       pci_info(pdev, "VL805 RAM firmware version %08x\n", version);
        return 0;
 }
 EXPORT_SYMBOL_GPL(rpi_firmware_init_vl805);

Here are the my results with 3x Raspberry Pi 4:

VL805 EEPROM firmware version 000137ad
VL805 EEPROM firmware version 00013701
VL805 RAM firmware version 000137ad

So the whole patch series is:

Tested-by: Stefan Wahren <stefan.wahren@i2se.com>

