On Tue, 9 Sep 2025 22:44:16 +0200, Michal Pecio wrote: > On Tue, 9 Sep 2025 14:29:20 +0300, Andy Shevchenko wrote: > > Not really. It prints unnecessary long values on 32-bit machines > > making an impression that something works somewhere in 64-bit > > address space. > > The %016llx format you are alluding to is used in two error messages > actually seen by users, that's an issue. My crazy personal preference > would be %08llx, but I concede it's unprofessional, so %pad it seems. Actually, I take this back. I think that leading zeros are evil and I agree this message is bad. But I don't understand why 64 bit users should put up with this: [ 140.106751] xhci_hcd 0000:07:00.0: Event dma 0x00000000ffeec7f0 for ep 2 status 13 not part of TD at 00000000ffeec800 - 00000000ffeec800 [ 140.476573] xhci_hcd 0000:07:00.0: Event dma 0x00000000ffeec1a0 for ep 2 status 13 not part of TD at 00000000ffeec1b0 - 00000000ffeec1b0 [ 140.502855] xhci_hcd 0000:07:00.0: Event dma 0x00000000ffeecd60 for ep 2 status 13 not part of TD at 00000000ffeecd70 - 00000000ffeecd70 [ 141.225300] xhci_hcd 0000:07:00.0: Event dma 0x00000000ffeeb970 for ep 2 status 13 not part of TD at 00000000ffeeb980 - 00000000ffeeb980 when we can have this: [ 419.967755] xhci_hcd 0000:07:00.0: Event dma 0xffc34760 for ep 2 status 13 not part of TD at 0xffc34770 - 0xffc34770 [ 420.100611] xhci_hcd 0000:07:00.0: Event dma 0xffc34bc0 for ep 2 status 13 not part of TD at 0xffc34bd0 - 0xffc34bd0 [ 420.360917] xhci_hcd 0000:07:00.0: Event dma 0xffc34e70 for ep 2 status 13 not part of TD at 0xffc34e80 - 0xffc34e80 [ 421.719530] xhci_hcd 0000:07:00.0: Event dma 0xffc35770 for ep 2 status 13 not part of TD at 0xffc35780 - 0xffc35780 with a simple change (anything wrong with u64 cast here?): - xhci_err(xhci, "Event dma %pad for ep %d status %d not part of TD at %016llx - %016llx\n", - &ep_trb_dma, ep_index, trb_comp_code, + xhci_err(xhci, "Event dma %#08llx for ep %d status %d not part of TD at %#08llx - %#08llx\n", + (u64) ep_trb_dma, ep_index, trb_comp_code, These zeros only add noise, and in many cases make difference between line wrapping or not because this is longer than 99% of kernel messages and some people want their terminal window not to take the whole screen. The main thing we care about here are the last 3-4 digits and we could have made it little more than (ep_trb_dma & 0xffff) long ago, but then Niklas asked "what about correlation with tracing/debugfs/dyndbg?", so it was left the way it is. Regards, Michal
