Messages in this thread | | | Subject | Re: [PATCH 1/1] USB: PHY: JZ4770: Fix uninitialized value written to HW register | From | Zhou Yanjie <> | Date | Thu, 27 Aug 2020 23:35:30 +0800 |
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Hi
在 2020/8/27 下午9:50, Paul Cercueil 写道: > > > Le jeu. 27 août 2020 à 16:25, Felipe Balbi <balbi@kernel.org> a écrit : >> >> Hi, >> >> Paul Cercueil <paul@crapouillou.net> writes: >>>>> @@ -172,7 +172,8 @@ static int ingenic_usb_phy_init(struct usb_phy >>>>> *phy) >>>>> return err; >>>>> } >>>>> >>>>> - priv->soc_info->usb_phy_init(phy); >>>>> + reg = priv->soc_info->usb_phy_init(phy); >>>>> + writel(reg, priv->base + REG_USBPCR_OFFSET); >>>> >>>> not fixing any bug. >>>> >>>> Looking at the code, the bug follows after this line. It would >>>> suffice >>>> to read REG_USBPCR_OFFSET in order to initialize reg. This bug fix >>>> could >>>> have been a one liner. >>> >>> There's no need to re-read a register when you have the value readily >>> available. It just needs to be returned from the usb_phy_init >>> callbacks. But yes, it's not a one-liner. >> >> there's a difference between making a bug fix and reworking the behavior >> of the driver ;-) > > The one-liner is actually what changes the behavior of the driver, > since previously the code did not read back the register. > > In this case I guess it's fine, because the register does not have > volatile bits. > >>>>> @@ -195,19 +196,15 @@ static void ingenic_usb_phy_remove(void *phy) >>>>> usb_remove_phy(phy); >>>>> } >>>>> >>>>> -static void jz4770_usb_phy_init(struct usb_phy *phy) >>>>> +static u32 jz4770_usb_phy_init(struct usb_phy *phy) >>>> >>>> not a bug fix >>>> >>>>> { >>>>> - struct jz4770_phy *priv = phy_to_jz4770_phy(phy); >>>>> - u32 reg; >>>>> - >>>>> - reg = USBPCR_AVLD_REG | USBPCR_COMMONONN | >>>>> USBPCR_IDPULLUP_ALWAYS >>>>> | >>>>> + return USBPCR_AVLD_REG | USBPCR_COMMONONN | >>>>> USBPCR_IDPULLUP_ALWAYS | >>>>> USBPCR_COMPDISTUNE_DFT | USBPCR_OTGTUNE_DFT | >>>>> USBPCR_SQRXTUNE_DFT | >>>>> USBPCR_TXFSLSTUNE_DFT | USBPCR_TXRISETUNE_DFT | >>>>> USBPCR_TXVREFTUNE_DFT | >>>>> USBPCR_POR; >>>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>> >>>> not a bug fix >>>> >>>>> } >>>>> >>>>> -static void jz4780_usb_phy_init(struct usb_phy *phy) >>>>> +static u32 jz4780_usb_phy_init(struct usb_phy *phy) >>>> >>>> not a bug fix >>>> >>>>> @@ -216,11 +213,10 @@ static void jz4780_usb_phy_init(struct >>>>> usb_phy *phy) >>>>> USBPCR1_WORD_IF_16BIT; >>>>> writel(reg, priv->base + REG_USBPCR1_OFFSET); >>>>> >>>>> - reg = USBPCR_TXPREEMPHTUNE | USBPCR_COMMONONN | USBPCR_POR; >>>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>>> + return USBPCR_TXPREEMPHTUNE | USBPCR_COMMONONN | USBPCR_POR; >>>> >>>> not a bug fix >>>> >>>>> } >>>>> >>>>> -static void x1000_usb_phy_init(struct usb_phy *phy) >>>>> +static u32 x1000_usb_phy_init(struct usb_phy *phy) >>>> >>>> not a bug fix >>>> >>>>> { >>>>> struct jz4770_phy *priv = phy_to_jz4770_phy(phy); >>>>> u32 reg; >>>>> @@ -228,13 +224,12 @@ static void x1000_usb_phy_init(struct usb_phy >>>>> *phy) >>>>> reg = readl(priv->base + REG_USBPCR1_OFFSET) | >>>>> USBPCR1_WORD_IF_16BIT; >>>>> writel(reg, priv->base + REG_USBPCR1_OFFSET); >>>>> >>>>> - reg = USBPCR_SQRXTUNE_DCR_20PCT | USBPCR_TXPREEMPHTUNE | >>>>> + return USBPCR_SQRXTUNE_DCR_20PCT | USBPCR_TXPREEMPHTUNE | >>>>> USBPCR_TXHSXVTUNE_DCR_15MV | USBPCR_TXVREFTUNE_INC_25PPT | >>>>> USBPCR_COMMONONN | USBPCR_POR; >>>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>> >>>> not a bug fix >>>> >>>>> } >>>>> >>>>> -static void x1830_usb_phy_init(struct usb_phy *phy) >>>>> +static u32 x1830_usb_phy_init(struct usb_phy *phy) >>>> >>>> not a bug fix >>>> >>>>> { >>>>> struct jz4770_phy *priv = phy_to_jz4770_phy(phy); >>>>> u32 reg; >>>>> @@ -246,9 +241,8 @@ static void x1830_usb_phy_init(struct usb_phy >>>>> *phy) >>>>> USBPCR1_DMPD | USBPCR1_DPPD; >>>>> writel(reg, priv->base + REG_USBPCR1_OFFSET); >>>>> >>>>> - reg = USBPCR_IDPULLUP_OTG | USBPCR_VBUSVLDEXT >>>>> | USBPCR_TXPREEMPHTUNE | >>>>> + return USBPCR_IDPULLUP_OTG | USBPCR_VBUSVLDEXT | >>>>> USBPCR_TXPREEMPHTUNE | >>>>> USBPCR_COMMONONN | USBPCR_POR; >>>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>> >>>> not a bug fix >>> >>> Well, if you don't like my bug fix, next time wait for my Reviewed-by. >> >> why so angry? Take a break every once in a while. Besides, someone else >> already sent the oneliner before you ;-) > > I'm just pissed that this patch has not been tested. I don't like > sloppy work. > This is my fault. This error occurred in the v5 version, but was corrected in the v6 version, but I don't know why v5 was merged into the mainline and v6 was not merged, which caused this problem.
>> In any case, why should I wait for your Reviewed-by? Get maintainer >> doesn't list you as the maintainer for it. Do you want to update >> MAINTAINERS by any chance? > > Yes, I thought I was (I'm maintainer of all Ingenic drivers), that > also explains why I wasn't Cc'd for the oneliner patch you mentioned... > I checked again, get_maintainer did not give the correct information, which caused my script to not add Paul to the cc list. > IIRC Zhou has a patch to move the driver to drivers/phy/, I'll add > myself as maintainer once it's moved there. > I'll resend it soon.
Thanks and best regards!
> -Paul >
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