linux-kernel - Re: [PATCH v4 3/3] Input: ili210x

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Message-ID: <cd8f71db-c2d1-4c85-8148-83822762a916@mailbox.org>
Date: Wed, 21 Jan 2026 23:42:55 +0100
From: Marek Vasut <marek.vasut@...lbox.org>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc: linux-input@...r.kernel.org, Conor Dooley <conor+dt@...nel.org>,
 Frank Li <Frank.Li@....com>, Job Noorman <job@...rman.info>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Rob Herring <robh@...nel.org>,
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-renesas-soc@...r.kernel.org
Subject: Re: [PATCH v4 3/3] Input: ili210x - add support for polling mode

On 1/21/26 6:23 AM, Dmitry Torokhov wrote:
> On Tue, Jan 20, 2026 at 11:50:53PM +0100, Marek Vasut wrote:
>> On 1/20/26 7:31 PM, Dmitry Torokhov wrote:
>>> Hi Marek,
>>>
>>> On Sat, Jan 17, 2026 at 01:12:04AM +0100, Marek Vasut wrote:
>>>> @@ -860,16 +893,12 @@ static ssize_t ili210x_firmware_update_store(struct device *dev,
>>>>    	 * the touch controller to disable the IRQs during update, so we have
>>>>    	 * to do it this way here.
>>>>    	 */
>>>> -	scoped_guard(disable_irq, &client->irq) {
>>>> -		dev_dbg(dev, "Firmware update started, firmware=%s\n", fwname);
>>>> -
>>>> -		ili210x_hardware_reset(priv->reset_gpio);
>>>> -
>>>> -		error = ili210x_do_firmware_update(priv, fwbuf, ac_end, df_end);
>>>> -
>>>> -		ili210x_hardware_reset(priv->reset_gpio);
>>>> -
>>>> -		dev_dbg(dev, "Firmware update ended, error=%i\n", error);
>>>> +	if (client->irq > 0) {
>>>> +		scoped_guard(disable_irq, &client->irq) {
>>>> +			error = ili210x_firmware_update_noirq(dev, fwbuf, ac_end, df_end);
>>>> +		}
>>>
>>> You already have a scope here, no need to establish a new one:
>>>
>>> 		guard(disable_irq)(&client->irq);
>>> 		error = ili210x_firmware_update_noirq(dev, fwbuf, ac_end, df_end);
>>
>> This part ^ I do not understand. If there is no IRQ defined in DT, I need to
>> call ili210x_firmware_update_noirq() without the guard because I cannot
>> disable_irq() with client->irq < 0, else I need to call
>> ili210x_firmware_update_noirq() within the scoped_guard() to disable IRQs to
>> avoid spurious IRQs that would interfere with the firmware update ?
> 
> You do not need to use scoped_guard() because you already define a scope
> in your if statement:
> 
> if (client->irq > 0) {
> 	guard(disable_irq)(&client->irq);
> 	error = ili210x_firmware_update_noirq(dev, fwbuf, ac_end, df_end);
> } else {
> 	error = ili210x_firmware_update_noirq(dev, fwbuf, ac_end, df_end);
> }
> 
> This is sill a bit awkward. Maybe we could add to interrupt.h

Let me do the part above in V5 , and then the part below as a separate 
follow up patch/series. I already added the later in tree so it won't be 
lost. Does that work for you ?

> void __disable_valid_irq(unsigned int irq)
> {
> 	if (irq > 0)
> 		disable_irq(irq);
> }
> 
> void __enable_valid_irq(unsigned int irq)
> {
> 	if (irq > 0)
> 		enable_irq(irq);
> }
> 
> DEFINE_LOCK_GUARD_1(disable_valid_irq, int,
> 		    disable_valid_irq(*_T->lock), enable_valid_irq(*_T->lock))
> 
> and then we'd be able to keep the driver as is (just adjust the type of
> the original scoped_guard).
> 
>>
>>> BTW, not a fan of the "_noirq" suffix... Maybe drop it and add
>>> lockdep_is_held() there?
>>
>> This part I understand even less, how does lockdep play into this ? The
>> scoped_guard() disables and enables IRQs if they are available.
> 
> Ah, sorry, brainfart on my part. I got confused by _noirq suffix.
OK