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> > 542 if (spi->irq <= 0) { > > 543 dev_err(&pdev->dev, "invalid IRQ %d for SPI controller\n", spi->irq); > > 544 ret = spi->irq; > > 545 goto error_release_master; > > 546 } > > 547 > > 548 ret = devm_request_irq(&pdev->dev, spi->irq, mchp_corespi_interrupt, > > 549 IRQF_SHARED, dev_name(&pdev->dev), master); > > 550 if (ret) { > > 551 dev_err(&pdev->dev, "could not request irq: %d\n", ret); > > 552 goto error_release_master; > > 553 } > > 554 > > 555 spi->clk = devm_clk_get(&pdev->dev, NULL); > > 556 if (!spi->clk || IS_ERR(spi->clk)) { > > ^^^^^^^^ > > NULL > > > > --> 557 ret = PTR_ERR(spi->clk); > > > > ret is 0/success. > > > > Normally when functions like this return NULL, you're supposed to just > > accept the NULL and add tests for it to avoid NULL related bugs. In > > this driver if spi->clk is NULL then it leads to spi_hz == 0 which leads > > to a divide by zero bug. So it's not clear which way to go on this? > > Fix the error code or add more checks for NULL? > > Am I being dumb here, or should the null check just be removed like > every other driver? As in, devm_clk_get will only return a valid > clk or an IS_ERR() condition. It can return NULL if CONFIG_HAVE_CLK is disabled. I don't know the hardware or if that CONFIG_ is essential for booting. > > The correct solution seems to me to be remove the !spi->clk check? That's the normal solution, yes. But if you do that, then please add a check to prevent the divide by zero: `grep -w clk drivers/spi/spi-microchip-core.c` regards, dan carpenter