> -----Original Message----- > From: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx> > Sent: Friday, December 20, 2024 2:13 PM > To: Carlos Song <carlos.song@xxxxxxx> > Cc: Andi Shyti <andi.shyti@xxxxxxxxxx>; Frank Li <frank.li@xxxxxxx>; > kernel@xxxxxxxxxxxxxx; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; > festevam@xxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Clark Wang > <xiaoning.wang@xxxxxxx>; Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> > Subject: [EXT] Re: [PATCH v5] i2c: imx: support DMA defer probing > > Caution: This is an external email. Please take care when clicking links or > opening attachments. When in doubt, report the message using the 'Report this > email' button > > > On Fri, Dec 20, 2024 at 05:59:38AM +0000, Carlos Song wrote: > > > > So we make this logic. Anyway we let the I2C controller registered > > > > whether > > > DMA is available or not(except defer probe). > > > > Ignoring ENODEV and EPROBE_DEFER makes it looks like nothing > > > > happened if > > > DMA is defer probed or not enabled(This is an expected). > > > > However we still need i2c DMA status is known when meet an > > > > unexpected > > > error, so we use dev_err_probe() to print error. > > > > > > Why dev_err_probe() instead of dev_err()? > > > > > Hi, > > In patch V2 discussion, Marc suggested just return dev_err_probe(), > > but I don't accept it so I choose to use dev_err_probe() to print error in V3.[1] > In this case, the two APIs have the same function, do you mean dev_err() is more > suitable? > > Yes, dev_err_probe() should be used in combination with return. For > example: > return dev_err_probe(...); > > It will pass the return value on exit of the function and optionally print of the > error message if it is not EPROBE_DEFER. Practically it replace commonly used > coding pattern: > if (ret == -EPROBE_DEFER) { > return ret; > } else if (ret) { > dev_err(..); > return ret; > } > Hi, Get your good point. I will change my code in V6: + ret = i2c_imx_dma_request(i2c_imx, phy_addr); + if (ret) { + if (ret == -EPROBE_DEFER) + goto clk_notifier_unregister; + else if (ret == -ENODEV) + dev_dbg(&pdev->dev, "Only use PIO mode\n"); + else + dev_err(&pdev->dev, "Failed to setup DMA, only use PIO mode\n"); + } I think this is what you want to see, right? > -- > Pengutronix e.K. | > | > Steuerwalder Str. 21 | > http://www.pen/ > gutronix.de%2F&data=05%7C02%7Ccarlos.song%40nxp.com%7C2950266755a > 241c00a9208dd20bd5cf2%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0 > %7C638702719862691439%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGki > OnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ > %3D%3D%7C0%7C%7C%7C&sdata=aIuzJP0v5C6HzOCGnCHobK9Llml3thHclTwu > CjD13IM%3D&reserved=0 | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 > | > Amtsgericht Hildesheim, HRA 2686 | Fax: > +49-5121-206917-5555 |