Re: [Patch v7 2/4] memory: tegra: Add MC error logging on tegra186 onward

From: Ashish Mhetre
Date: Thu Apr 14 2022 - 01:32:20 EST




On 4/14/2022 2:43 AM, Dmitry Osipenko wrote:
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On 4/13/22 12:40, Ashish Mhetre wrote:
+irqreturn_t tegra30_mc_handle_irq(int irq, void *data)
{
struct tegra_mc *mc = data;
+ unsigned int bit, channel;
unsigned long status;
- unsigned int bit;

- /* mask all interrupts to avoid flooding */
- status = mc_readl(mc, MC_INTSTATUS) & mc->soc->intmask;
+ if (mc->soc->num_channels) {
+ u32 global_status;
+ int err;
+
+ global_status = mc_ch_readl(mc, MC_BROADCAST_CHANNEL, MC_GLOBAL_INTSTATUS);

This will crash if mc->bcast_ch_regs = ERR_PTR(-EINVAL) for older dtbs.

Actually interrupts won't occur till we write MC_INTMASK register from
broadcast channel with appropriate intmask value. I have added check in
tegra_mc_probe() while registering irq which will write MC_INTMASK from
broadcast only when mc->bcast_ch_regs is initialized i.e.
!IS_ERR(mc->bcast_ch_regs).
So interrupt handler won't be triggered at all if
mc->bcast_ch_regs = ERR_PTR(-EINVAL).