Re: [PATCH v13 5/5] usb: xhci: provide a debugfs hook for erasing rom

Greg Kroah-Hartman
2020-05-14T10:27:58Z

On Wed, May 13, 2020 at 02:45:54PM +0200, Greg Kroah-Hartman wrote:
> On Wed, May 13, 2020 at 03:36:19PM +0300, Mathias Nyman wrote:
> > On 6.5.2020 9.00, Vinod Koul wrote:
> > > run "echo 1 > /sys/kernel/debug/renesas-usb/rom_erase" to erase
> > > firmware when driver is loaded.
> > >
> > > Subsequent init of driver shall reload the firmware
> > >
> > > Signed-off-by: Vinod Koul <vkoul@kernel.org>
> > > ---
> > > drivers/usb/host/xhci-pci-renesas.c | 33 +++++++++++++++++++++++++++++
> > > 1 file changed, 33 insertions(+)
> > >
> > > diff --git a/drivers/usb/host/xhci-pci-renesas.c b/drivers/usb/host/xhci-pci-renesas.c
> > > index f7d2445d30ec..fa32ec352dc8 100644
> > > --- a/drivers/usb/host/xhci-pci-renesas.c
> > > +++ b/drivers/usb/host/xhci-pci-renesas.c
> > > @@ -2,6 +2,7 @@
> > > /* Copyright (C) 2019-2020 Linaro Limited */
> > >
> > > #include <linux/acpi.h>
> > > +#include <linux/debugfs.h>
> > > #include <linux/firmware.h>
> > > #include <linux/module.h>
> > > #include <linux/pci.h>
> > > @@ -170,6 +171,8 @@ static int renesas_fw_verify(const void *fw_data,
> > > return 0;
> > > }
> > >
> > > +static void debugfs_init(struct pci_dev *pdev);
> > > +
> > > static bool renesas_check_rom(struct pci_dev *pdev)
> > > {
> > > u16 rom_status;
> > > @@ -183,6 +186,7 @@ static bool renesas_check_rom(struct pci_dev *pdev)
> > > rom_status &= RENESAS_ROM_STATUS_ROM_EXISTS;
> > > if (rom_status) {
> > > dev_dbg(&pdev->dev, "External ROM exists\n");
> > > + debugfs_init(pdev);
> > > return true; /* External ROM exists */
> > > }
> > >
> > > @@ -449,6 +453,34 @@ static void renesas_rom_erase(struct pci_dev *pdev)
> > > dev_dbg(&pdev->dev, "ROM Erase... Done success\n");
> > > }
> > >
> > > +static int debugfs_rom_erase(void *data, u64 value)
> > > +{
> > > + struct pci_dev *pdev = data;
> > > +
> > > + if (value == 1) {
> > > + dev_dbg(&pdev->dev, "Userspace requested ROM erase\n");
> > > + renesas_rom_erase(pdev);
> > > + return 0;
> > > + }
> > > + return -EINVAL;
> > > +}
> > > +DEFINE_DEBUGFS_ATTRIBUTE(rom_erase_ops, NULL, debugfs_rom_erase, "%llu\n");
> > > +
> > > +static struct dentry *debugfs_root;
> > > +
> > > +static void debugfs_init(struct pci_dev *pdev)
> > > +{
> > > + debugfs_root = debugfs_create_dir("renesas_usb", NULL);
> >
> > This will create a renesas_usb directory right under debugfs root.
> > xhci has its own struct dentry xhci_debugfs_root;
> > Use that as parent instead
>
> Ah, I misssed that, a follow-on patch can do this, right?

Actually, a whole new series with this changed is good, I didn't take
these for now, for some reason I thought I had.

thanks,

greg k-h